I am seeking some assistance. I have a player that keeps getting disconnected due to the same issue. The console will say (Kicked: Steam: InvalidAuthSession). 

Does anyone know what might be causing this? If so, is there anything I can do to fix it? Thank you!

That player needs to restart steam. That basically means that steam cant authenticate there session so it just kicks them. Restarting steam usually fixes the issue unless steam is having issues in that players area

Razor14150

That player needs to restart steam. That basically means that steam cant authenticate there session so it just kicks them. Restarting steam usually fixes the issue unless steam is having issues in that players area

double post , deleted

Razor14150

That player needs to restart steam. That basically means that steam cant authenticate there session so it just kicks them. Restarting steam usually fixes the issue unless steam is having issues in that players area

or the player has a slowed down internet connection . could be a lack of memory (?) , or running too many programs in the background