FxV stops collecting all new data. We are making heavy use of Groovy scripts.
This problem is due to a deadlock in the actual Java 6 API standard library class 'groovy.lang.MetaClassImpl' used by the groovy script. And that deadlock, in turn, causes a deadlock in FxV systems that make very heavy use of Groovy scripts. Though this is not a FXV defect per se, it is still being tracked as FXV-287
This defect will only manifest on FxV systems that make very heavy use of Groovy scripts. Those are the systems that will be most impacted by synchronizing.
Try to use fewer groovy scripts or do not put them under as much load. FxV does not respond to the reboot command in the Setup Program, it needs to be hard booted to break the deadlock.
Fixed in FxV version 5.6.5--this version uses Java 7. The latest version of FxV can be downloaded at: