Hi Sean,
Glad to hear your issue now resolved
>> What did you do exactly to fix this so that I know for future reference?
It seems like there is one missing folder called 'logs' in the themes folder of this app. I just upload the missing folder and its files into your site and it fixed your issue
JOOMLA/media/com_easysocial/apps/user/blog/themes/default/logs
Hope this help and have a nice day