Can't seem to replicate this error on our build, can you share your save file with us - it will speed up the production of a patchfix by a lot!
On Windows saves are stored in:
C:\Users\ [username] \AppData\Roaming\RenPy\ACADEMY34-v0.2.3
You can upload it to any cloud site of your liking (on Mega or Limewire for example)