Sometimes you might see the message "Not permitted! You don't have access to this issue!"
This means that you do not have permission to view the issue for some reason. It can be your specific user or the usergroup you belong to in the Permission tab on the issue (read more here) or it can be that you do not have access to the project at all.
If you think you should have permissions to view the issue your are trying to access you need to contact a administrator for the project within your organisation. The email addresses that come up in the message belong to any user that are administrator or project administrator on the project.
You can also see who belongs to these group by going to the project > Users tab. If you want to make any changes you can click on "Manage users for this workspace"
In the general Settings > Roles/Groups > User groups you can see/change what usergroup is in fact an administrator or project administrator.
Note that changes to user's usergroups will change their permissions to perform actions or view information in the system.