The worst progressbars I have to deal with are in CATIA V5. Most often it stands still at 5% and than suddenly jumps to 95% at which point you can start waiting again... . If we have to open/convert a big file, my colleagues and I jusualy just check the taskmanager to see if anything is still working or if the program died. On a nother note: If you open an assamby in CATIA don't be surprised to read something like "2342 parts of 103 loaded"  under the progressbar. 🤦‍♀️