First I would check the settings on your logs, what level is being logged right now and what level are you viewing.
There is a possibility that your log got so large it can't be easily processed by Thingworx.
On the server check root/ThingworxStorage/Logs and see if you see the script log there and how big it is.
I would perhaps stop tomcat, remove the logs and then restart.
Make sure you check the settings in the logging subsystem as well, those determine how large a log file it will create before 'rolling over'.
