Modularity runs fine on the network I'm examining if "Use Weights" is unchecked. If it's checked, I get this:

java.lang.ArrayIndexOutOfBoundsException: -1
at org.gephi.statistics.plugin.Modularity$CommunityStructure.zoomOut(Modularity.java:338)
at org.gephi.statistics.plugin.Modularity$CommunityStructure.access$400(Modularity.java:122)
at org.gephi.statistics.plugin.Modularity.execute(Modularity.java:452)
at org.gephi.statistics.plugin.Modularity.execute(Modularity.java:396)
at org.gephi.statistics.StatisticsControllerImpl.execute(StatisticsControllerImpl.java:154)
at org.gephi.statistics.StatisticsControllerImpl$3.run(StatisticsControllerImpl.java:141)
[catch] at org.gephi.utils.longtask.api.LongTaskExecutor$RunningLongTask.run(LongTaskExecutor.java:251)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)