I'm getting errors after my simgallery installation that's preventing my site from loading

Hi guys,
I'm getting errors from simgallery after it was installed that are preventing my site from loading. I know it says to turn off error messages, but they are preventing the notification window from opening in jomsocial when they are turned off.
Can you help?
IveI've aattached a copy of the error message as a screen grab.

Thanks
Adam