Mark thank you very much for not forgetting
Works in me test forum.
1) Problem with case sensitive user names (Stratis, stratis)
2) and basic, the error user will see is the common
You do not have permission to access this page. This could be due to one of several reasons: bla, bla, bla...
I don't know if it can have a field that we can write our message.
even in two occasions:
* Users|Restricted Scripts
* Users|Restricted Forums
separated field to input error message user will see.
If its to much, as it is will do