Please describe your issue in as much detail as possible:
When launching a Source engine game mod (HL2: MMod in this case), the entire steam client window gets covered by a semi-transparent overlay with an error message (see the screenshot), making it not respond to mouse events. The library is still somewhat controllable via a keyboard. The problem is fixed only by restarting steam. "Refresh" button cannot be pressed due to the fact that the mouse doesn't work in this state.
The problem does not seem to occur when launching the mod from the steam library overview
Your system information
Please describe your issue in as much detail as possible:
When launching a Source engine game mod (HL2: MMod in this case), the entire steam client window gets covered by a semi-transparent overlay with an error message (see the screenshot), making it not respond to mouse events. The library is still somewhat controllable via a keyboard. The problem is fixed only by restarting steam. "Refresh" button cannot be pressed due to the fact that the mouse doesn't work in this state.
The problem does not seem to occur when launching the mod from the steam library overview