Created attachment 131916 [details] Kra file to reproduce Krita 4.4.0-beta1 crashes when you open a kra with reference image(s).
Created attachment 131917 [details] crash log backtrace from gdb
I can confirm this for the 4.4.0-beta1 appimage with the .kra file attached and another file with an embedded reference image. This does not happen in the 4.3.0 appimage.
*** This bug has been marked as a duplicate of bug 426839 ***