It is strange. I found out that on my other blog (newly installed), when I click on installed plugins, the following address is opened:
https://www.gadgetmag.dk/wp-admin/plugins.php
however, on the blog with the problem, instead of the above address:
https://www.mobilmag.dk/wp-admin/plugins.php?page=plugins.php
Which gives the permission error. If I remove the thing after question mark, everything works perfect.
how come? Two blogs with same version, 3.5.1, and both with same user permission, they open two different addresses!
Wished someone could point me to the right direction ??