diff --git a/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldObstacleCompactSoftshell.java b/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldObstacleCompactSoftshell.java
index 3f1d6a88f9f78d1c9d4a3e66848322c00cb64472..750dcc88f4d00c3ac5b9b959a7e226f497d85257 100644
--- a/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldObstacleCompactSoftshell.java
+++ b/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldObstacleCompactSoftshell.java
@@ -61,10 +61,10 @@ public class PotentialFieldObstacleCompactSoftshell implements PotentialFieldObs
 			double currentPotential = 0;
 
 			if (distance < this.width) {
-				currentPotential = this.height * MathUtil.expAp(2 / (Math.pow(distance / (this.width), 2) - 1));
+				currentPotential = this.height * Math.exp(2 / (Math.pow(distance / (this.width), 2) - 1));
 			}
 			if (distance < radius) {
-				currentPotential += 100000 * MathUtil.expAp(1 / (Math.pow(distance / radius, 2) - 1));
+				currentPotential += 100000 * Math.exp(1 / (Math.pow(distance / radius, 2) - 1));
 			}
 
 			if (potential < currentPotential)
diff --git a/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldPedestrianCompactSoftshell.java b/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldPedestrianCompactSoftshell.java
index aa9fd25de19a98b44653cafe1dfc7233293c1d34..e7a91b0448a4ed6e757fa652849c3e73e1b35f6c 100644
--- a/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldPedestrianCompactSoftshell.java
+++ b/VadereSimulator/src/org/vadere/simulator/models/potential/PotentialFieldPedestrianCompactSoftshell.java
@@ -62,14 +62,14 @@ public class PotentialFieldPedestrianCompactSoftshell implements PotentialFieldA
 			double factor = this.attributes.getIntimateSpaceFactor();
 
 			if (distance < personalWidth + radii) {
-				potential += this.height * MathUtil.expAp(4 / (Math.pow(distance / (personalWidth + radii), (2 * perPower)) - 1));
+				potential += this.height * Math.exp(4 / (Math.pow(distance / (personalWidth + radii), (2 * perPower)) - 1));
 			}
 			if (distance < this.intimateWidth + radii) {
 				potential += this.height / factor
-						* MathUtil.expAp(4 / (Math.pow(distance / (this.intimateWidth + radii), (2 * intPower)) - 1));
+						* Math.exp(4 / (Math.pow(distance / (this.intimateWidth + radii), (2 * intPower)) - 1));
 			}
 			if (distance < radii) {
-				potential += 1000 * MathUtil.expAp(1 / (Math.pow(distance / radii, 4) - 1));
+				potential += 1000 * Math.exp(1 / (Math.pow(distance / radii, 4) - 1));
 			}
 		}
 		return potential;
diff --git a/VadereSimulator/src/org/vadere/simulator/projects/ScenarioRun.java b/VadereSimulator/src/org/vadere/simulator/projects/ScenarioRun.java
index 4b811609fe4ea54c2a31bf397af8f1c5a263ce86..d0b185de45636fca32b7707f258c9147a45181e5 100644
--- a/VadereSimulator/src/org/vadere/simulator/projects/ScenarioRun.java
+++ b/VadereSimulator/src/org/vadere/simulator/projects/ScenarioRun.java
@@ -68,30 +68,37 @@ public class ScenarioRun implements Runnable {
 	@Override
 	public void run() {
 		try {
-			logger.info(String.format("Initializing scenario. Start of scenario '%s'...", scenario.getName()));
-			scenarioStore.getTopography().reset();
-
-			MainModelBuilder modelBuilder = new MainModelBuilder(scenarioStore);
-			modelBuilder.createModelAndRandom();
-
-			final MainModel mainModel = modelBuilder.getModel();
-			final Random random = modelBuilder.getRandom();
-			
-			// prepare processors and simulation data writer
-			if(scenarioStore.attributesSimulation.isWriteSimulationData()) {
-				processorManager = dataProcessingJsonManager.createProcessorManager(mainModel);
+			/**
+			 * To make sure that no other Thread changes the scenarioStore object during the initialization of a scenario run
+			 * this is an atomic operation with respect to the scenarioStore. We observed that with Linux 18.04 KUbunto
+			 * the GUI-Thread changes the scenarioStore object during a simulation run. Which can lead to any unexpected behaviour.
+			 */
+			synchronized (scenarioStore) {
+				logger.info(String.format("Initializing scenario. Start of scenario '%s'...", scenario.getName()));
+				scenarioStore.getTopography().reset();
+
+				MainModelBuilder modelBuilder = new MainModelBuilder(scenarioStore);
+				modelBuilder.createModelAndRandom();
+
+				final MainModel mainModel = modelBuilder.getModel();
+				final Random random = modelBuilder.getRandom();
+
+				// prepare processors and simulation data writer
+				if(scenarioStore.attributesSimulation.isWriteSimulationData()) {
+					processorManager = dataProcessingJsonManager.createProcessorManager(mainModel);
+				}
+
+				// Only create output directory and write .scenario file if there is any output.
+				if(processorManager != null && !processorManager.isEmpty()) {
+					createAndSetOutputDirectory();
+					scenario.saveToOutputPath(outputPath);
+				}
+
+				sealAllAttributes();
+
+				// Run simulation main loop from start time = 0 seconds
+				simulation = new Simulation(mainModel, 0, scenarioStore.name, scenarioStore, passiveCallbacks, random, processorManager);
 			}
-
-			// Only create output directory and write .scenario file if there is any output.
-			if(processorManager != null && !processorManager.isEmpty()) {
-                createAndSetOutputDirectory();
-                scenario.saveToOutputPath(outputPath);
-            }
-
-			sealAllAttributes();
-
-			// Run simulation main loop from start time = 0 seconds
-			simulation = new Simulation(mainModel, 0, scenarioStore.name, scenarioStore, passiveCallbacks, random, processorManager);
 			simulation.run();
 
 		} catch (Exception e) {