You do not have sufficient permissions … only at /wp-admin/

Briefly, the problem I’m having is that I can’t access the main Dashboard (and the link for it has disappeared from the menu), but I can access everything else in the admin area and it all seems to be working fine.

The detail of how it happened is below.

Yesterday, I tried to install Dreamglow Scroll Triggered Box on my blog. I knew it hadn’t been tested with 4.0, but I have it active on a blog running 3.92, so I thought I’d give it a go. I figured the worst that could happen was it wouldn’t work!!

I didn’t notice any problems, but decided not to use it after all. I deactivated it, then went through my plugins list and deleted that and 3 or 4 other inactive plugins that I’d installed then decided weren’t quite what I was looking for.

Next, I did some work on creating a lightbox popup with a premium plugin (Hybrid Connect) that I’ve never had any problems with.

Once I’d done as much as I wanted for the night, I saved my work and went to click the Dashboard link. (For some reason, I always tend to leave my blogs on Dashboard when I shut down.) It was missing.

I was a bit puzzled, so I closed the tab, re-opened, and tried to load louisevenison.com/wp-admin/ That’s when I got the permissions error.

I can get into the admin area by going straight to one of the other pages, and everything seems to be working fine. I just can’t access the main dashboard.

I went through the database and checked all the prefixes, but can’t see anything wrong. I use the standard wp_ prefix, it’s a single installation, and I’m the only registered user on the blog.

Beyond that, I have no idea how to fix it! Any suggestions?