Internal Server Error after Failed Update

Hi there,
I've tried to update EasySocial and have now a blank screen, both front-end and back-end and can't access anything.
I've turned error reporting on via .htaccess and it says

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, admin and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

I updated by uploading com_easysocial_component_pro_1.3.28_joomla3.0.zip to the /administrator/components/com_easysocial/setup/packages folder.

I'm still on J2.5.28 but wanted to (finally, I know) update do J3.4 today.

Any help would be greatly appreciated. I have a backup I made pre-update, but it would be great if I wouldn't have to restore from backup.

Thank you!!