Don't panic, this is an OLD Moodle BUG that has been around now for over three years...
https://moodle.org/mod/forum/discuss.php?d=147792#p646347
It is not so much where you move from in your Moodle site, but more to do with the page in which you land.
At the moment it appears to be rearing its ugly head in Bootstrap based themes.
If you get this kind of error, please report it here and copy/paste your particular Error message and Stack Trace which is usually listed below the error.
Thanks
Mary
Don't panic Mrs Evans!!!
I am getting this error using the clean bootstrap theme trying to use the customsql plugin.
I am not sure where to get the stack trace.
Hi you should not be getting this error with the latest version of Moodle
It tends to happen when a block region exists in the code but not specified in the theme's config.php.
However, in your case it might be something you have added to the theme files, or something in the plug-in that is looking for a region that does not exist, for the same reasons as mentioned previously. Can you explain more about the SQL plug-in as I am not familiar with it.
Thanks
Mary
Could it be this https://moodle.org/plugins/view.php?plugin=report_customsql by Tim Hunt?
Dear Mary and Brandon,
I just tried to replicate on Moodle 2.5.2+ (Build: 20130927) with version 2013062400 of the report and cannot.
Cheers,
Gareth