diff --git a/.gitignore b/.gitignore
index e43b0f9..74d54ac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .DS_Store
+tmpdir
diff --git a/environment.yml b/environment.yml
index 161c0e2..8cf2fae 100644
--- a/environment.yml
+++ b/environment.yml
@@ -2,6 +2,9 @@ name: eventdisplay-release-tests
 channels:
   - conda-forge
 dependencies:
+  - python>=3.8
+  - numpy
+  - matplotlib
   - pandoc
   - pre-commit
   - towncrier
@@ -11,3 +14,4 @@ dependencies:
 # activate: conda activate eventdisplay-release-tests
 # update (conda/mamba): conda env update -f environment.yml --prune
 # update (micromamba): micromamba update -f environment.yml
+# update (micromamba): micromamba update -n eventdisplay-release-tests -f environment.yml
diff --git a/release_tests/montecarlo/irf_plotting/irf_plotting.sh b/release_tests/montecarlo/irf_plotting/irf_plotting.sh
index 02ddf03..7a41c35 100755
--- a/release_tests/montecarlo/irf_plotting/irf_plotting.sh
+++ b/release_tests/montecarlo/irf_plotting/irf_plotting.sh
@@ -18,6 +18,7 @@ CUT="NTel3-PointSource-Hard-TMVA-BDT"
 CUT="NTel2-PointSource-Soft-TMVA-BDT"
 CUT="NTel2-PointSource-Moderate-TMVA-BDT"
 CUT="NTel2-PointSource-Moderate"
+echo "WARNING: CUT is hardwired to $CUT (for now)"
 # Comparison plots - version and simtype hardwired
 COMPAREVERSION="v492"
 COMPARESIMTYPE="CARE_202404"
diff --git a/release_tests/montecarlo/mc_data_comparison/.gitignore b/release_tests/montecarlo/mc_data_comparison/.gitignore
deleted file mode 100644
index 15c6bf7..0000000
--- a/release_tests/montecarlo/mc_data_comparison/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-tmpdir
diff --git a/release_tests/montecarlo/mc_data_comparison/README.md b/release_tests/montecarlo/mc_data_comparison/README.md
index a89720b..6a61489 100644
--- a/release_tests/montecarlo/mc_data_comparison/README.md
+++ b/release_tests/montecarlo/mc_data_comparison/README.md
@@ -1,20 +1,97 @@
-# MC / data comparison
+# MC / Data Comparison
 
-Scripts and tools to compare MC distributions with results from the Crab Nebula.
+**No apptainer usage!**
 
-Fill and plot distributions with
+Scripts and tools to compare Monte Carlo (MC) distributions with observational results from the Crab Nebula.
+
+## Quick Start
 
 ```console
-./compareDatawithMC.sh <runparameter file> <SZE/MZE/LZE/WOBBLE>
+./compareDatawithMC.sh <runparameter file> <SZE|MZE|LZE|WOBBLE>
 ```
 
-Requires as input:
+Where `<SZE|MZE|LZE|WOBBLE>` specifies the observation conditions:
+
+- `SZE`: Small zenith angles (0-25°, 0.5° wobble)
+- `MZE`: Medium zenith angles (40-50°, 0.5° wobble)
+- `LZE`: Large zenith angles (50-70°, 0.5° wobble)
+- `WOBBLE`: Large wobble offsets (MC at 1° wobble, summer atmosphere only)
+
+NOTE! The zenith angle bins are different compared to those used in the Crab Nebula analysis.
+
+## Prerequisites
+
+### Input Data Requirements
+
+- MC simulation files for each minor epoch (organized by atmosphere type)
+- Crab Nebula mscw results for each minor epoch
+- Run lists for Crab observations (generated separately)
+
+## Preparation Steps
+
+Before running the comparison, you must generate the Crab run lists:
+
+```console
+# From release_tests/sources/Crab/
+./runlist_generator_from_anasum_log.sh <run parameter file> <anasum-results-directory>
+```
+
+This generates run lists for minor epochs, zenith angle ranges, and atmosphere types.
+The run lists are saved in `EventDisplay_Release_<version>/Crab/runlists/`.
+
+## Running the Comparison
+
+### Step 1: Prepare Run Parameter File
+
+The `<run parameter file>` must contain the following fields (one per line):
 
-- MC files for each minor epoch
-- Crab mscw results for each minor epoch
+```text
+* VERSION         <eventdisplay_version>  # e.g., V6
+* SIMTYPE         <simulation_type>       # e.g., CARE, CARE_RedHV
+* ATMOSPHERE      <atmosphere_id>         # e.g., 61*, 62*
+* EPOCH           <epoch_id>              # e.g., V4*, V5*, V6*
+* CRAB_NSB        <nsb_level>             # e.g., 0, 1, or NOTSET
+```
+
+Fields marked with `*` support wildcards for multiple values.
+
+### Step 2: Execute Comparison
+
+```console
+cd release_tests/montecarlo/mc_data_comparison/
+./compareDatawithMC.sh <path/to/run\ parameter\ file> SZE
+```
+
+This will:
+
+1. Parse the run parameter file
+2. Locate MC simulation files based on epoch and atmosphere
+3. Find corresponding Crab observational data
+4. Submit Condor jobs for each combination
+5. Generate comparison plots as PDF files
+
+### Step 3: Monitor Progress
+
+- Condor jobs are submitted with resource requests: 4000MB RAM, 10GB disk
+- Temporary symbolic links are created in: `{output_dir}/tmp/{uuid}/`
+- **Note**: Temporary directories must be cleaned up manually after completion
+
+## Output Structure
+
+Results are written to:
+
+```text
+EventDisplay_Release_<version>/mc_data_comparison/<analysis_type><disp>/<simulation_type>/
+├── <epoch>_ATM<atm>_<ELE>_<wobble>_<nsb>/
+│   ├── mcdatacomparison.runparameter
+│   ├── mcdatacomparison.root
+│   ├── mcdatacomparison.log
+│   └── *.pdf                    # Comparison plots
+└── tmp/                         # Temporary symlinks (manual cleanup required)
+```
 
-**important:**
-first run linking of epochs from `../../sources/Crab/`: `./runlist_generator.sh V6`
-(or for any other epoch)
+## Special Cases
 
-Output and plots are written as PDFs into the `../../../../EventDisplay_Release_<version>/mc_data_comparison/` directories
+- **CARE_RedHV simulations**: Handled with modified BDT cut (BDT=0 instead of 1)
+- **Summer vs Winter Atmosphere**: Automatically selected based on epoch suffix ('s' or 'w')
+- **Wobble Mode**: Forces atmosphere 61 (summer) and 1.0° wobble offset
diff --git a/release_tests/montecarlo/mc_data_comparison/compareDatawithMC.sh b/release_tests/montecarlo/mc_data_comparison/compareDatawithMC.sh
index 440978b..0a58bca 100755
--- a/release_tests/montecarlo/mc_data_comparison/compareDatawithMC.sh
+++ b/release_tests/montecarlo/mc_data_comparison/compareDatawithMC.sh
@@ -4,13 +4,13 @@
 #
 # requires:
 # - MC files for each minor epoch
-# - Crab results for each minor epoch (read from Crab runlists; used pre-processed data)
+# - Crab results for each minor epoch (read from Crab run lists; used pre-processed data)
 
 set -e
 
 if [[ $# < 2 ]]; then
 echo "
-  ./compareDatawithMC.sh <runparameter file> <SZE/MZE/LZE/WOBBLE>
+  ./compareDatawithMC.sh <run parameter file> <SZE/MZE/LZE/WOBBLE>
   --> choose zenith angle / wobble range
       SZE: small zenith angles (0.5 deg wobble)
       MZE: medium large zenith angles (0.5 deg wobble)
@@ -23,9 +23,9 @@ exit
 fi
 
 ###########################
-# read runparameter file
+# read run parameter file
 if [[ ! -e ${1} ]]; then
-   echo "Error, runparameter file not found: ${1}"
+   echo "Error, run parameter file not found: ${1}"
    exit
 fi
 # Eventdisplay version
@@ -58,10 +58,8 @@ fi
 # Directory for simulations
 SIMDIR=${VERITAS_IRFPRODUCTION_DIR}/${VERSION}/${ANALYSISTYPE}/$SIMTYPE/
 if [[ ! -e ${SIMDIR} ]]; then
-   if [[ ! -e ${SIMDIR} ]]; then
-       echo "Error: simulation directory not found: $SIMDIR"
-       exit
-   fi
+    echo "Error: simulation directory not found: $SIMDIR"
+    exit
 fi
 # Directory for mscw data files
 DDIR="$VERITAS_PREPROCESSED_DATA_DIR/${ANALYSISTYPE}/mscw/"
@@ -123,7 +121,7 @@ do
         ZEMAX="50."
     elif [[ $ELE = "LZE" ]]
     then
-        ZEMIN="50"
+        ZEMIN="50."
         ZEMAX="70."
         simfile="55deg_${MCWOFF}wob_NOISE${NSB}.mscw.root"
     # wobble set (everything not 0.5 deg)
@@ -216,8 +214,5 @@ do
         $EVNDISPSCRIPTS/helper_scripts/UTILITY.condorSubmission.sh ${FSCRIPT}.sh 4000M 10G
         condor_submit ${FSCRIPT}.sh.condor
 
-        continue
-
-
     done
 done
diff --git a/release_tests/sources/Crab/README.md b/release_tests/sources/Crab/README.md
index 34f56af..b1c9330 100644
--- a/release_tests/sources/Crab/README.md
+++ b/release_tests/sources/Crab/README.md
@@ -43,7 +43,7 @@ for
 Combine files using pre-processed anasum files and run list generated in step before:
 
 ```bash
-./anasum_yearly.sh <runparameter file> <anasum-run-wise directory>
+./anasum_from_runlists.sh <run-parameter file> <anasum-run-wise directory>
 ```
 
 ## Plotting
diff --git a/release_tests/sources/Crab/plot_all.sh b/release_tests/sources/Crab/plot_all.sh
index 5486d36..8564882 100755
--- a/release_tests/sources/Crab/plot_all.sh
+++ b/release_tests/sources/Crab/plot_all.sh
@@ -19,8 +19,6 @@ ODIR="${2}/$CUT"
 echo "Output directory: $ODIR"
 mkdir -p "$ODIR"
 
-PDIR=$(pwd)
-
 # copy anasum log files to release test directory
 for F in $LFIL; do
     TF=$(basename $F .combined.root)
diff --git a/release_tests/sources/Crab/plot_energy_spectra.C b/release_tests/sources/Crab/plot_energy_spectra.C
index 3fc3e6d..882d484 100644
--- a/release_tests/sources/Crab/plot_energy_spectra.C
+++ b/release_tests/sources/Crab/plot_energy_spectra.C
@@ -14,6 +14,8 @@
 
 #include "TF1.h"
 
+R__LOAD_LIBRARY($EVNDISPSYS/lib/libVAnaSum.so)
+
 #include "../../utilities/parameters.C"
 #include "../../utilities/printutilities.C"
 
diff --git a/release_tests/sources/Crab/plot_lightcurves.C b/release_tests/sources/Crab/plot_lightcurves.C
index 458f068..5b341a7 100644
--- a/release_tests/sources/Crab/plot_lightcurves.C
+++ b/release_tests/sources/Crab/plot_lightcurves.C
@@ -13,6 +13,8 @@
 #include <string>
 #include <vector>
 
+R__LOAD_LIBRARY($EVNDISPSYS/lib/libVAnaSum.so)
+
 #include "../../utilities/parameters.C"
 #include "../../utilities/printutilities.C"
 
diff --git a/release_tests/sources/Crab/plot_sensitivity.C b/release_tests/sources/Crab/plot_sensitivity.C
index b8c4fd8..84de9dd 100644
--- a/release_tests/sources/Crab/plot_sensitivity.C
+++ b/release_tests/sources/Crab/plot_sensitivity.C
@@ -4,6 +4,7 @@
  */
 
 #include <string>
+R__LOAD_LIBRARY($EVNDISPSYS/lib/libVAnaSum.so)
 
 #include "../../utilities/parameters.C"
 #include "../../utilities/printutilities.C"
diff --git a/release_tests/sources/Crab/plot_sensitivity_from_anasum_log.py b/release_tests/sources/Crab/plot_sensitivity_from_anasum_log.py
new file mode 100644
index 0000000..1409d6a
--- /dev/null
+++ b/release_tests/sources/Crab/plot_sensitivity_from_anasum_log.py
@@ -0,0 +1,187 @@
+"""Plot sensitivity diagnostics from anasum log files.
+
+Reads anasum log files from an input directory and writes a PNG summary figure.
+
+Usage: python plot_sensitivity_from_anasum_log.py [input_dir] [output_png]
+"""
+
+import argparse
+import glob
+import os
+import re
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+# Parse input directory argument
+parser = argparse.ArgumentParser(description="Plot sensitivity metrics from anasum log files.")
+parser.add_argument(
+    "input_dir",
+    nargs="?",
+    default=".",
+    help="Directory containing anasum log files (default: current directory)",
+)
+parser.add_argument(
+    "output_png",
+    nargs="?",
+    default="anasum_analysis_plots.png",
+    help="Output PNG filename (default: anasum_analysis_plots.png)",
+)
+args = parser.parse_args()
+
+if not os.path.isdir(args.input_dir):
+    raise SystemExit(f"Input directory does not exist: {args.input_dir}")
+
+log_files = sorted(
+    glob.glob(os.path.join(args.input_dir, "*anasum*V6_20*ATM*SZE_0.5deg.combined.log"))
+)
+
+if not log_files:
+    raise SystemExit(f"No anasum log files found in: {args.input_dir}")
+
+epochs = []
+on_off_summary_rates = []
+off_summary_rates = []
+crab_001_times = []
+all_elevations = []
+all_on_rates = []
+all_off_rates = []
+
+for filepath in log_files:
+    print(f"Processing file: {filepath}")
+    with open(filepath, "r") as f:
+        content = f.read()
+
+        # Extract epoch from filename (e.g., V6_2023_2023s_ATM62 or V6_2014_2015_ATM61)
+        basename = os.path.basename(filepath)
+        epoch_match = re.search(r"(V6_[^_]+_\d+[a-z]*)_ATM\d+", basename)
+        if not epoch_match:
+            # Try alternative pattern for ATM61 files
+            epoch_match = re.search(
+                r"(V6_[^_]+_\d+[a-z]*)_ATM\d+", basename.replace("_SZE_0.5deg.combined", "")
+            )
+        if not epoch_match:
+            continue
+        epoch = epoch_match.group(1)
+
+        # Extract summary on/off rates
+        rate_match = re.search(r"Rates \(on/Off\): (\d+\.\d+)\s+(\d+\.\d+)", content)
+
+        # Extract 0.01 Crab time in hours from the sensitivity table
+        lines = content.split("\n")
+        crab_time = None
+        in_table = False
+        for line in lines:
+            if "[h]" in line:
+                in_table = True
+                continue
+            if in_table and line.strip().startswith("0.01"):
+                parts = line.split()
+                if len(parts) >= 3:
+                    try:
+                        crab_time = float(parts[-1])
+                    except ValueError:
+                        pass
+                break
+
+        # Extract all elevation and rate values from RUN lines
+        el_values = []
+        on_rates = []
+        off_rates = []
+        for line in lines:
+            el_match = re.search(r"RUN\s+\d+.*at\s+(\d+),\s+(-?\d+)\s+deg\s+El\.,\s+Az", line)
+            rate_match_line = re.search(r"Rates:\s+([\d.]+).*background:\s+([\d.]+)", line)
+            if el_match:
+                el_values.append(int(el_match.group(1)))
+            if rate_match_line:
+                on_rates.append(float(rate_match_line.group(1)))
+                off_rates.append(float(rate_match_line.group(2)))
+
+        # Only add data if we have all values and non-empty arrays
+        if rate_match and crab_time is not None and el_values and on_rates and off_rates:
+            epochs.append(epoch)
+            on_off_summary_rates.append(float(rate_match.group(1)))
+            off_summary_rates.append(float(rate_match.group(2)))
+            crab_001_times.append(crab_time)
+            all_elevations.append(np.array(el_values))
+            all_on_rates.append(np.array(on_rates))
+            all_off_rates.append(np.array(off_rates))
+
+# Calculate average elevation per epoch for sensitivity plot
+avg_elevations = [np.mean(el) for el in all_elevations]
+
+# Create plots - 4 rows: 2x2 + 2 extra
+fig, axs = plt.subplots(4, 2, figsize=(14, 20))
+
+# Plot 1: On Rate vs Epoch
+axs[0, 0].plot(epochs, on_off_summary_rates, "o-", color="blue")
+axs[0, 0].set_xlabel("Epoch")
+axs[0, 0].set_ylabel("On Rate")
+axs[0, 0].set_title("On Rate vs Epoch")
+axs[0, 0].tick_params(axis="x", rotation=45)
+
+# Plot 2: Off Rate vs Epoch
+axs[0, 1].plot(epochs, off_summary_rates, "s-", color="orange")
+axs[0, 1].set_xlabel("Epoch")
+axs[0, 1].set_ylabel("Off Rate")
+axs[0, 1].set_title("Off Rate vs Epoch")
+axs[0, 1].tick_params(axis="x", rotation=45)
+
+# Plot 3: Violin plot of Elevations per Epoch
+axs[1, 0].violinplot(all_elevations, positions=range(len(epochs)), widths=0.8, showmeans=True)
+axs[1, 0].set_xticks(range(len(epochs)))
+axs[1, 0].set_xticklabels(epochs, rotation=45, ha="right")
+axs[1, 0].set_xlabel("Epoch")
+axs[1, 0].set_ylabel("Elevation [deg]")
+axs[1, 0].set_title("Elevation Distribution per Epoch")
+
+# Plot 4: Violin plot of On Rates per Epoch
+axs[1, 1].violinplot(all_on_rates, positions=range(len(epochs)), widths=0.8, showmeans=True)
+axs[1, 1].set_xticks(range(len(epochs)))
+axs[1, 1].set_xticklabels(epochs, rotation=45, ha="right")
+axs[1, 1].set_xlabel("Epoch")
+axs[1, 1].set_ylabel("On Rate")
+axs[1, 1].set_title("On Rate Distribution per Epoch")
+
+# Plot 5: Violin plot of Off Rates per Epoch
+axs[2, 0].violinplot(all_off_rates, positions=range(len(epochs)), widths=0.8, showmeans=True)
+axs[2, 0].set_xticks(range(len(epochs)))
+axs[2, 0].set_xticklabels(epochs, rotation=45, ha="right")
+axs[2, 0].set_xlabel("Epoch")
+axs[2, 0].set_ylabel("Off Rate")
+axs[2, 0].set_title("Off Rate Distribution per Epoch")
+
+# Plot 6: 0.01 Crab Sensitivity Time vs Epoch
+axs[2, 1].plot(epochs, crab_001_times, "s-", color="purple")
+axs[2, 1].set_xlabel("Epoch")
+axs[2, 1].set_ylabel("0.01 Crab Time [h]")
+axs[2, 1].set_title("0.01 Crab Sensitivity Time vs Epoch")
+axs[2, 1].tick_params(axis="x", rotation=45)
+
+# Plot 7: Sensitivity vs Average Elevation
+# Color points red if epoch year >= 2020
+colors = [
+    (
+        "red"
+        if "2020" in epoch
+        or "2021" in epoch
+        or "2022" in epoch
+        or "2023" in epoch
+        or "2024" in epoch
+        or "2025" in epoch
+        or "2026" in epoch
+        else "blue"
+    )
+    for epoch in epochs
+]
+axs[3, 0].scatter(avg_elevations, crab_001_times, c=colors, alpha=0.7)
+axs[3, 0].set_xlabel("Average Elevation [deg]")
+axs[3, 0].set_ylabel("0.01 Crab Time [h]")
+axs[3, 0].set_title("Sensitivity vs Elevation")
+
+# Hide the empty subplot
+axs[3, 1].axis("off")
+
+plt.tight_layout()
+plt.savefig(args.output_png, dpi=300, bbox_inches="tight")
+print(f"Processed {len(epochs)} files. Plots saved as {args.output_png}")
diff --git a/release_tests/sources/Crab/plot_skymaps.C b/release_tests/sources/Crab/plot_skymaps.C
index 98d905a..5c8fda3 100644
--- a/release_tests/sources/Crab/plot_skymaps.C
+++ b/release_tests/sources/Crab/plot_skymaps.C
@@ -11,6 +11,8 @@
 #include <string>
 #include <vector>
 
+R__LOAD_LIBRARY($EVNDISPSYS/lib/libVAnaSum.so)
+
 #include "../../utilities/parameters.C"
 #include "../../utilities/printutilities.C"
 
diff --git a/release_tests/sources/Crab/runlist_generator_from_anasum_log.sh b/release_tests/sources/Crab/runlist_generator_from_anasum_log.sh
index 913b3b1..7783734 100755
--- a/release_tests/sources/Crab/runlist_generator_from_anasum_log.sh
+++ b/release_tests/sources/Crab/runlist_generator_from_anasum_log.sh
@@ -99,6 +99,11 @@ do
       echo "Run $R - log file not found: ${ANASUMLOG}"
       exit
    fi
+   # Skip runs without 4-telescope cuts
+   if ! grep -q "VGammaHadronCuts::printCutSummary() (ntel=4" "${ANASUMLOG}"; then
+      echo "RUN $R not a 4-telescope run..skipping"
+      continue
+   fi
    echo "DATADIR ${ANASUMLOG}"
    # read and extract run info from files
    INSTRUMENT_EPOCH=$(grep "Instrument epoch selected" "${ANASUMLOG}" | head -n 1 | awk '{print $NF}')
@@ -117,7 +122,7 @@ do
        OBSL="stdHV"
    fi
    ELEV=$(grep "mean elevation" "${ANASUMLOG}" | head -n 1 | awk '{print $3}')
-   EL=$(echo $ELEV | awk -v e=$ELEV '{if (e > 50 ) {print "SZE"} else if (e > 40 ) {print "MZE"} else if (e > 30 ) {print "LZE"} else {print "BZE"}}')
+   EL=$(echo $ELEV | awk -v e=$ELEV '{if (e > 60 ) {print "SZE"} else if (e > 45 ) {print "MZE"} else if (e > 35 ) {print "LZE"} else {print "BZE"}}')
    WOBBLESTRING=$(grep "Wobble offsets (currE)" "${ANASUMLOG}")
    n_offset=$(echo "$WOBBLESTRING" | head -n 1 | awk '{print $5}')
    w_offset=$(echo "$WOBBLESTRING" | head -n 1 | awk '{print $7}')
diff --git a/release_tests/sources/Crab/runlist_releaseTestingV6.dat b/release_tests/sources/Crab/runlist_releaseTestingV6.dat
index da6d0e3..e5d6a73 100644
--- a/release_tests/sources/Crab/runlist_releaseTestingV6.dat
+++ b/release_tests/sources/Crab/runlist_releaseTestingV6.dat
@@ -814,7 +814,6 @@
 104174
 104199
 104201
-104202
 104251
 104252
 104253
@@ -992,7 +991,6 @@
 113299
 113303
 113352
-113375
 113515
 113637
 113689
diff --git a/release_tests/utilities/parameters.C b/release_tests/utilities/parameters.C
index a6880a8..cf49eeb 100644
--- a/release_tests/utilities/parameters.C
+++ b/release_tests/utilities/parameters.C
@@ -17,8 +17,9 @@
  * Helper for ROOT macros: load libVAnaSum from environment.
  * Search order:
  *   1) $VERITAS_VANASUM_LIBRARY
- *   2) $EVNDISP/lib/libVAnaSum.so
- *   3) ROOT library path via "libVAnaSum.so"
+ *   2) $EVNDISPSYS/lib/libVAnaSum.so
+ *   3) $EVNDISP/lib/libVAnaSum.so
+ *   4) ROOT library path via "libVAnaSum.so"
  */
 bool loadVAnaSumLibrary()
 {
@@ -35,6 +36,14 @@ bool loadVAnaSumLibrary()
         iLibPath = iEnvLib;
     }
     if( iLibPath.size() == 0 )
+    {
+        const char* iEvndispSys = gSystem->Getenv( "EVNDISPSYS" );
+        if( iEvndispSys )
+        {
+            iLibPath = string( iEvndispSys ) + "/lib/libVAnaSum.so";
+        }
+    }
+    if( iLibPath.size() == 0 )
     {
         const char* iEvndisp = gSystem->Getenv( "EVNDISP" );
         if( iEvndisp )
@@ -45,21 +54,26 @@ bool loadVAnaSumLibrary()
 
     if( iLibPath.size() > 0 && !gSystem->AccessPathName( iLibPath.c_str() ) )
     {
-        if( gSystem->Load( iLibPath.c_str() ) >= 0 )
+        // Use gROOT->ProcessLine to properly load the library and its dictionaries
+        string loadCmd = "R__LOAD_LIBRARY(" + iLibPath + ");";
+        int result = gROOT->ProcessLine( loadCmd.c_str() );
+        if( result >= 0 )
         {
             iLibraryLoaded = true;
             return true;
         }
     }
 
-    if( gSystem->Load( "libVAnaSum.so" ) >= 0 )
+    // Try with just the library name
+    int result = gROOT->ProcessLine( "R__LOAD_LIBRARY(libVAnaSum.so);" );
+    if( result >= 0 )
     {
         iLibraryLoaded = true;
         return true;
     }
 
     cout << "Error: unable to load libVAnaSum.so. "
-         << "Set VERITAS_VANASUM_LIBRARY or EVNDISP." << endl;
+         << "Set VERITAS_VANASUM_LIBRARY, EVNDISPSYS, or EVNDISP." << endl;
     return false;
 }