Delete Users Causing Error

Hi,

I have deleted some users from EasySocial, but now I am seeing this warning message at the top of the screen when in EasyDiscuss.

Warning

JUser: :_load: Unable to load user with ID: 840



JUser: :_load: Unable to load user with ID: 842

These users had posts. What can be done to remove the warnings and please can you tell me the correct procedure for removing users so that EasyDiscuss doesn't complain?

Thanks.