I think the problem is when you start with an older file, especially one created in an older version of AC. I had a similar problem and solved it by doing what Joeri suggested, but instead of just changing a few fills I did the following:
1. Open attribute manager.
2. On the right pane I opened the AC template that came with archicad.
3. Select all the fills from the template and overwrite them to your project (might be smart to do a "save as" before all of this).
4. Now my library parts are OK.
Of course this will probably F-up your other fills big time, but I figured it was worth the hassle to change a few fills and save the headache of dealing with the library parts. Find & Select was a big help in getting these updated.
cheers,
JB
AC 21 (8002) & 22 USA
Mac OSX 10.14.5 on MacBook Pro 2.3GHz Intel i7, 16GB Ram, NVIDIA GeForce GT 750M 2GB VRAM, 500GB SSD