Errors on a start up

I've been getting same 2 errors on starting fc since few days the first one being:

"Apologies! An error has occurred. You may be able to continue, but some parts may not work properly.

Error [tw-user-script-0]: App is not defined.",

and the second one just after confirming the previous one:

"Apologies! An error has occurred. You may be able to continue, but some parts may not work properly.

Error [setupVars]: <>: bad range expression: App is not defined.".

Cleared cache and cookies, tried on firefox and chrome on windows 7.