Everquest Mouse on Secondary PC - A Solution
mouse issues (disappears, won't click)
from 
Stardock Forums
Stardock Forums
Just a courtesy for folks playing Everquest and having mouse difficulties out of the blue with their second PC as I know Multiplicity is a preferred utility app for EQ users. May also apply in remote desktop scenarios.
Ran into this problem and eventually found the solution in my case on Reddit:
This is a known issue where EQ doesn't work well without a real pointing device connected at startup. Remote desktop apps have the same issue."
ยท 3m
IE Ensure a physical mouse is connected to the PC. Tried reinstalls, rests, purges to no avail. replugged in the mouse I disconnected yesterday, problem solved.
Regards
Athilnaur.