When using an incompatible plugin, Confluence will report an exception without an accompanying stack trace - for example the NullPointerException below:

2008-08-10 08:40:36,609 ERROR [http-8080-Processor6] [atlassian.plugin.web.DefaultWebInterfaceManager] filterFragmentsByCondition Could not evaluate condition: java.lang.NullPointerException
 -- url: /display/sample/Home | userName: ogawa | action: viewpage | page: 589828

It is impossible to know which plugin is failing based on the exception above.

This can be improved by including the stack trace of the error so we know where the problem actually lives.

Please include the following in method filterFragmentsByCondition :

            catch (Throwable t)
            {
                if (log.isDebugEnabled())
                    log.debug("Could not evaluate condition for descriptor: " + descriptor, t);
                else
                    log.warn("Could not evaluate condition for descriptor: " + descriptor + ", with throwable: " + t);
                iterator.remove();
            }