If you are using Spring MVC you may see this message at times when generating HTML from your JSPs.
The full text of the message is:
500 Internal Server Error
Servlet error: An exception occurred. The current application deployment descriptors do not allow for including it in this response. Please consult the application log for details.
Looking at the log you will not see any error or exception whatsoever.
The problem is the coding in the JSP is accessing a variable in the model incorrectly. Either a getter is missing or a field was changed, added, removed – etc… Unfortunately this is all occurring in the bowels of Spring so the exception never percolates up.
If it was working fine before some recent change, then you are in luck. The recent change is the culprit.
If you are on a bigger team or have been out of the loop for a while then you are out of luck. You may need to do a binary search on the coding (remove 1/2, see if it works, remove 1/4, see if it works, …)