I had this same error. MY problem was plugin related (see my post here [http://wordpress.org/support/topic/an-unknown-error-plug-in-add-new-search])
Upon further review of my server ERROR LOG I determined the problem was one of three(3) plugins creating various php WARNINGS and FATAL ERRORS…
- Google Analytics
- Google Analytics Dashboard
- WP-Gallery-Remote
Having deactivated each of these, one at a time, the condition progressively improved. However, for some reason, as long as they remained in my “plugins” directory, they continued to cause problems.
Once I actually deleted these plugins, everything seems to be working properly again.
Hope this helps others!
Don’t be stupid, learn from MY mistakes.
I KNEW it had to be something simple!
That was IT!
Thanks Doc!
