I get a long console dialogue that starts with
"Script warning, "Hedon.ipk3:textures.txt" line24: Texture 'TZANA0 references itself as a patch"
Then there is a long list with the same problem in different liness,
then unknown patch 'IDBARREL1 in texture 'IBARA0'
then there are more script warings about unknown class names in different lines and it all
ends with : "Savegame is from a different level"

This happened today when i started it up , yesterday there was no problem , restarting doesnt help

Check the post "Patch 2.1.0" from several days ago. save games do not work across diff game versions.

Found that out also the hard way. They say to use the Testing Hub to restore progress manually.