how is possible some active users that have access to Jira projects got errors in access them days or weeks after? Im administrator and I often receive calls from some users complaining they can login but cant see anything and getting teh following error:
YOU CANT ACCESS ANY PROJECT AND ISSUES
you dont have the sufficient permissions to change your permissions contact your Jira Administrators.
I have to reset their password every time to allow them to get the access again to the projects and issues.
If you have a solution please answer me by email Thanks 
mibarra@reitmans.com