Drools 7.8.0 Exception in server.log

[Webster Homer]

I recently upgraded my application from Drools 6.5.0 to 7.8.0. The app runs in Wildfly, and seems to be working OK. Except that I see this in our Wildfly logs:

15:58:12,473 ERROR [org.drools.core.audit.WorkingMemoryFileLogger] (Thread-94) error: java.lang.OutOfMemoryError: Java heap space

at java.util.Arrays.copyOf(Arrays.java:3332)

at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:124)

at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:448)

at java.lang.StringBuilder.append(StringBuilder.java:136)

at org.drools.core.audit.WorkingMemoryFileLogger.writeToDisk(WorkingMemoryFileLogger.java:138)

at org.drools.core.audit.ThreadedWorkingMemoryFileLogger.writeToDisk(ThreadedWorkingMemoryFileLogger.java:54)

at org.drools.core.audit.ThreadedWorkingMemoryFileLogger$Writer.run(ThreadedWorkingMemoryFileLogger.java:69)

at java.lang.Thread.run(Thread.java:748)

 This doesn't seem to be causing a problem, it is happening during a rule session. Except for the error in the log I wouldn't have known  there was a problem.