After installing the Dark Rift update Dota crashes immediately after starting.

The screen turns black for a second (indicating that Dota actually starts) but returns to the desktop immediately.

My specs:

CPU: AMD A8-7600 (with deactivated on board graphics)
Graphics: AMD Radeon HD 6870
Mainboard: ASRock FM2A88X Extreme4+
8 GB RAM
HD: Corsair Force LS 60GB ATA

Ubuntu 14.04