I assume you mean you have time tracking enabled, and the permission to log work in the project, and the problem is when you put a time log in, it fails?
You need to give the errors you see, if any, and read the logs to see what the underlying errors are. The best trick here is to have the log being tailed in a terminal session window, and a second browser window where you can click a spell of and see what happens to the log.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.