I have an admin login I use with Web UI, but when I try to log in with WatchGuard System Manager, it says access denied by FIREBOX
The WatchGuard System Manager only allows connections using a Device Monitor (read-only) user account, such as the default Status account. This is why Access Denied error message pops up when trying to use an Admin account with the WSM. More information in the link below.
Eugene Torre | Support Engineer