I have 1.9.1 and finished building the site a few days ago. Nothing was ever wrong, now all of a sudden this morning I get an error on ALL pages frontend and admin:
There has been an error processing your request Exception printing is disabled by default for security reasons.
Error log record number: 189535875249
I have tried following the instructions here and here but it seems this is for a different version of Magento as I do not have var/report. So I have no idea where to even check this specific error but from everywhere I can see I need to manually create a tmp folder and edit some core code. I guess some Magento developer decided havint the install create the correct directories was not important and the better solution was to crash people's frontend a few days after install with no warning.
Can anyone tell me where the var/report has been moved?
var/report
then yourvar/
isn't writeable by the webserver and that's very likely your exception problem to begin with. Investigate why suddenly var isn't writeable (the installer checks if it is).