diff --git a/src/main/java/rv/comm/rcssserver/LogAnalyzerThread.java b/src/main/java/rv/comm/rcssserver/LogAnalyzerThread.java
index 25b881b..5c45348 100644
--- a/src/main/java/rv/comm/rcssserver/LogAnalyzerThread.java
+++ b/src/main/java/rv/comm/rcssserver/LogAnalyzerThread.java
@@ -87,7 +87,9 @@ public void run()
 		}
 		processFrame();
 
-		callback.finished(logfile.getNumFrames());
+		if (!aborted) {
+			callback.finished(logfile.getNumFrames());
+		}
 
 		try {
 			logfile.close();
@@ -127,7 +129,9 @@ private void processGoals()
 			int frame = logfile.getCurrentFrame();
 			int goalWindowFrames = Math.round((1 / stepSize) * LogPlayer.GOAL_WINDOW_SECONDS);
 			int viewFrame = Math.max(0, frame - goalWindowFrames);
-			callback.goalFound(new Goal(frame, viewFrame, scoringTeam));
+			if (!aborted) {
+				callback.goalFound(new Goal(frame, viewFrame, scoringTeam));
+			}
 		}
 
 		lastScoreLeft = scoreLeft;
@@ -155,7 +159,9 @@ private void processStepSize()
 				// estimate total number of frames
 				float halfTime = world.getGameState().getHalfTime();
 				int numFrames = Math.round(((1 / stepSize) * halfTime) + numPauseFrames);
-				callback.stepSizeFound(stepSize, numFrames);
+				if (!aborted) {
+					callback.stepSizeFound(stepSize, numFrames);
+				}
 				this.stepSize = stepSize;
 			}
 
diff --git a/src/main/java/rv/comm/rcssserver/LogPlayer.java b/src/main/java/rv/comm/rcssserver/LogPlayer.java
index fbfd20d..fa9a156 100644
--- a/src/main/java/rv/comm/rcssserver/LogPlayer.java
+++ b/src/main/java/rv/comm/rcssserver/LogPlayer.java
@@ -411,17 +411,29 @@ private void startAnalyzerThread(File file)
 			logAnalyzer.abort();
 		}
 		logAnalyzer = new LogAnalyzerThread(file, new LogAnalyzerThread.ResultCallback() {
+			/*
+			  A reference to the logfile reader is stored locally in the beginning of each callback.
+			  This prevents a NullPointerException when logfile is suddenly set to null in another thread.
+			 */
 			@Override
 			public void stepSizeFound(float stepSize, int numFrames)
 			{
+				ILogfileReader logfileReader = logfile;
+				if (logfile == null) {
+					return;
+				}
 				foundStepSize = true;
 				SECONDS_PER_FRAME = stepSize;
-				logfile.setNumFrames(numFrames);
+				logfileReader.setNumFrames(numFrames);
 			}
 
 			@Override
 			public void goalFound(Goal goal)
 			{
+				ILogfileReader logfileReader = logfile;
+				if (logfile == null) {
+					return;
+				}
 				goals.add(goal);
 				analyzedFrames = goal.frame;
 				stateChanged();
@@ -430,8 +442,12 @@ public void goalFound(Goal goal)
 			@Override
 			public void finished(int numFrames)
 			{
+				ILogfileReader logfileReader = logfile;
+				if (logfile == null) {
+					return;
+				}
 				LogPlayer.this.logAnalyzed = true;
-				logfile.setNumFrames(numFrames);
+				logfileReader.setNumFrames(numFrames);
 				analyzedFrames = numFrames;
 				stateChanged();
 			}