Seems I cannot login anymore in my WordPress.. Although, when I just go to my website, the upper menu is still visible. Only my 'Dashboard' in WordPress seems not accessible.
Therefore, I cannot update my WordPress version, and I keep getting an annoying error message in my WordPress:
[...] was called with an argument that is deprecated since version 2.0! Usage of user levels by plugins and themes is deprecated. Use roles and capabilities instead.
When I try to activate some Plugins, my website also shows this piece of error. Although there is nothing wrong with my Plugins nor my Themes..
Anyone knows what happens here?