Hello dpotuznik,
I tried on 4.27 Preview4, as well as the current 4.27 main branch, with some step files and could not reproduce.
Which version of the 4.27 are you using? Did you see if it failed also with step files from another source?
Would you be able to share the step file with us? If yes, send me a private message to discuss the setting up or a drive to exchange the file.
Bests,
Flavien.