http://bugs.winehq.org/show_bug.cgi?id=26835
--- Comment #118 from me@sythe.me 2011-05-11 18:16:25 CDT --- (In reply to comment #117)
According to GameValidation.log:
Starting validation of Portal 2 Validation failure: c:\program files\steam\steamapps\common\portal 2\portal2\bin\client.dll Validation failure: c:\program files\steam\steamapps\common\portal 2\portal2\bin\server.dll Validation complete: 2407 Total Files, 2 Failed Validation
Notice: Crash is inside of server.dll.
Which is why the "cracked" AKA fixed server.dll & client.dll by SKIDROW, when used, allow it to run perfectly.