Suppose you're missing the admin mode!

It can happen, just because a group membership is expired or you didn't set the expiry-offset
of an admin group.

It means, the system doesn't recognise, you're in the Admin-Group.
As a first step to solve this within WebGUI, you can't overcome to get into the code.
and put

return 1 if ( $uid eq "3" ); at the beginning of sub isInGroup in User.pm
(put it back, if you solved your problem)

After that you'll have to restart your WebGUI.

Since the membership of a group depends on the expireDate of the user-group relation, check an evt. repair those using a SQL Report:

#--------------------------------------

1. sql:

Select distinct groupName,groupings.groupId
from groups, groupings
where
groupings.groupId=groups.groupId
and groupings.groupId=groups.groupId
and isEditable = 1

order by groupName

2. sql, param:

query1:groupId

2. sql:

Select distinct username, users.userId, groupAdmin as isAdmin, from_unixtime(expireDate, '%Y-%m-%d') as ExpireDate
from users,groups,groupings
where
groups.groupId = ?
and users.userId=groupings.userId
and groupings.groupId=groups.groupId

order by username

Having this report within any WebGUI installation, isn't a bad idea!!

Another solution, just if you're not really using expiry times is to use a MySQL client and do:

update groupings set expireDate = 2114402400

That will last quite a long time to get the same problem again.