This page contains instructions relating to this error:
If you see this error when running Clover, you may need to increase the PermGen settings on your server JVM.
This error may sometimes come about when implementing Clover on large projects, due to Clover's additional requirements.
The required memory can be increased by setting the
-XX:MaxPermSize setting on the JVM.
See the OutOfMemoryError: PermGen KB article for more details.