A while ago we stated using those dreaded PC's in our Mac office.
We run Mac OSX server on an old G5 box.
We had little of no problems opening Archicad files on the PC, but once the PC saved the file back, any mac machine had untold problems opening the file.
I suspect it is the same issue you are having.
What is discovered was that the file path to locate the libraries was different between the PC and the mac. The issue was that the PC was using the route path through C:/ whereas the mac was using the path macintosh HD/.
Herein lies the problem.
The workaround was to open the file on the mac and escape the cannot find server thing. you should then find that you will have the load library dialogue come up.
If you find your libraries, you should not ahve anymore problem with the file until a PC opens it again.
I think from memory, if we had all the libraries installed locally on the PC, there were less issues with the mac after that.
I suspect it would be a similar if not the same issue with the DWG translators.
The file path.
good luck.
Cheers,
Karl.
Cheers,
Karl Barker.
27" iMac 3.6 Ghz Intel Core i9
32 Gig Ram
Mac OSX 10.14.6
AC 5.5 - AC22 (NZE)