AutoPLANT Error! It won't start. 'unable to read the AT.INI file

Question

I've seen the thread for this problem before and followed the instructions to no avail. I am running windows 7 64-bit autoplant v8i ss4. I still get this error even after following the suggestions in another post with the same problem.

Juan Pablo CD · Answer

Hi, in spite of this thread being old, maybe the solution i found could result useful for somebody else. 
I had exactly the same error, and none of the mentioned suggestions worked for me. 
I found that if you add to AutoCad Support File Search Path (in Options, File Tab), this path: 
"C:\ProgramData\Bentley\Plant V8i\CFG" (or the path to AT.INI in your machine) 
the problem disappears. 
No need to reinstall or to tinker with the register. 
Regards!