Darchitect

Working now don't know why

I just bought this game yesterday on my PC, but the game wasn't running as smoothly as I had hoped for, today I tried to play it on my MAC with OS X El Capitan but it gives me the following msg: You are logged in on another computer already playing "Offworld Trading Company". Launching "Offworld Trading Company" will disconnect the other session from steam. Then I get 2 options to press OK or CANCEL When I press OK a box pops titled "Offworld Trading Company - Steam" and r