The game is looking for an extension that the drivers don't support. A fix would require a change to the game and/or drivers.
@gdrewb-valve do you have still bad support from intel? It's sad especially for those, which have black screen issue in TF2 and propably this problem will be in other source engine based games...
I believe they're trying, but I don't know specifics about where they're at. Reporting issues directly to them is probably the best way to let them know you're having an issue.
Nothing extracted yet.
Critical: cannot find function glXSwapIntervalEXT
System info: http://pastebin.com/FdGQWLhE
Duplicate of
http://steamcommunity.com/app/206690/discussions/0/846939071405624512/
http://steamcommunity.com/app/221410/discussions/1/846939071171434042/
http://steamcommunity.com/app/221410/discussions/0/846939071214672602/