Is this everyone or just one person?
Can you try with the User tool to see if it renders from the default home page? If you can then this is a Mid Tier cache issue and therefore, shutdown tomcat and delete the contents of the following directories:
Single Sign On (SSO) for the BMC Remedy AR System, MyIT/SmartIT & ITSM
Did you try by restarting your webserver ?
This was happening on our development server just yesterday. In our case it wasn't MT cache because it happened on two different MT servers and in the User tool. When cache is ruled out I find the next culprit is usually a corrupt Active Link Guide setup as an entry point.A few months ago when we had this issue (again in dev) and there were errors in the arerror.log after restarting Remedy. This led us to the right AL Guide and a few other corrupt ALs. Yesterday that was not the case so in Dev Studio I opened up the AL Guides object list, sorted by modified descending and started opening the AL Guides. A few guides down one threw an error and would not open. Imported a copy from QA and the navigation links reappeared.It was the same AL Guide we had trouble with a while back. Although I am not sure why it started to act up again? The modified date was not changed recently, it showed the date the last time we fixed it.There is a way to get a log from the User tool that will show errors if all else fails. I don't remember the exact details right now and am on my phone so it is difficult to research at the moment. I think running the DB consistency check on the server will also find a bad AL Guide.Jason