For user cache issues, Robert's advice will work. Also Ctrl-F5 will do a 'force reload.'
However, there are instances where this may be insufficient:
- your servers are ignoring the 'no cache header' in the request and sends a server side cached page
- in a multiple server scenario, changes entered on one server have not cascade to your other servers
You can clear all the server side caches by attaching "security.caches" to your url: https://[servername].[domain].com/niku/nu#action:security.caches There, you'll see a means to clear some or all of your caches. Once cleared, system performance may be a bit slower, as the app rebuilds its caches.
If your changes are not cascading across your servers - you may have an issue with multi-cast/beacon - that can be a big topic and is discussed in other threads, so won't attempt to handle it here, now. If you need to go there, there are others that will be more efficient then me at answer related questions.
But, you can check to see if the problem is app server related - you can use the security.caches extension on machines were the problem exists and where it doesn't - on the Caches tab, underneath the "System Caches" label, you'll see the name of the app server that the user is logged into. If the simple tricks don't work and all the affected users are on the same app server, I'd start by using this page to clear all caches, then check to see if problem is gone. If not, if one server works and the other does not, you may have to dig into multicast/beacon issues.
Hopefully, Robert's info or Ctrl-F5 will be sufficient.