Hello,
I recently updated to 1.7.6.7 and I have had nothing but issues with the back office/admin log in. I currently cannot log in, I put in the information, the page refreshes instead of logging in. I have cleared my browser cache/cookies/etc, I have turned off my ad blocker, I have deleted unused files in the PHP, I have changed my PHP version (although I can't remember how I did that now or how to check). I am NOT proficient with this, I usually just Google things and try and work out what people mean by the suggested solutions, but I haven't been able to find anything, any information. Please help.
The solution was to restore the backup of public_html from before the most recent update.