Well, it seems that setting the DbTablePrefix for Chat module will actually create a conflict with Users tables, as both will have the same names.
I think it should behave in some other ways, maybe add DbTablePrefix + ChatUsers to avoid conflict.
Anyway, I got rid of the table prefixing of chat module and it works. Will wait for a fix and try again.
This question counts towards the assigned total questions per license? Because it seems like a bug, and not a support question.
Tks.