Had a bit of trouble with this wordpress blog site.
Looks like trouble came when installing that caching plugin, not sure though. Because it did work for a couple of weeks and really speeded up the site. The dashboard and other configuration pages, even the login page was completely messed up. Site itself worked though. Googdid workled a bit, nothing, weird. Anyway i tried a complete backup of the site, restore, no luck. Abvious, i had to try because it was just a few mouseclicks and gave me time to make some coffee. What did work:
– note the name (and password and so) of the MySQL database your wordpress login uses
– export that database (i use myPhpAdmin) and save
– throw away the wordpress installation completely
– reinstall a fresh one, choose the right database name and the theme
– import the previously saved database
Of course you can troubleshoot, but sometimes its faster to just get the data and reinstall.
I think its better to make a backup each time before installing (heavy impact) plugins. What is often recommended when a wordpress site runs into trouble is; just turn of the latest (few) or all plugins just installed or try the twenty whatever theme. But thats not much help when you dashboard is in some 6th dimension realm.
Not sure this recepy allways works. Sometimes you need to investigate and troubleshoot your problem. If you can use some help with that, let me know.