Can't find steam app user info - for a Source SDK 2006 mod

Hi, I’m new to modelling but good with instructions and nothing I do will help me convert my .qc files in 3DS Max using Wall Worm or GUIStudioMDL to .mdl files.

I searched and found this thread: http://forum.facepunch.com/showthread.php?t=1315773 - but nothing there helped either. I also cannot export VTF files but I got around that issue by manually converting each texture in Photoshop using nemstools VTF photoshop plugin. So now my only issue is trying to get the .qc files compiled due to that error in the title.

I also followed the instructions here: https://developer.valvesoftware.com/wiki/Can't_find_steam_app_user_info - but still no luck.

Any ideas what I might be doing wrong or how to fix it?
Here’s a screenshot of the error: