Because my lib wasn't up2date before then. 
And loading the part, it wasn't complete.
So the missing subfile made me realize the lib needed updating. And I hadn't had the situation before where an unofficial file needed an official (missing) subfile.
The PT says: Required (unofficial) subfiles: (none). So I assumed no subfile was needed. Only after reading the .dat and seeing the subfile, I checked the version of my lib and realized it was outdated.
Just my weird ways of working I guess
And loading the part, it wasn't complete. So the missing subfile made me realize the lib needed updating. And I hadn't had the situation before where an unofficial file needed an official (missing) subfile.
The PT says: Required (unofficial) subfiles: (none). So I assumed no subfile was needed. Only after reading the .dat and seeing the subfile, I checked the version of my lib and realized it was outdated.
Just my weird ways of working I guess