Can't "re-open" a AC10 file in AC9...

[Anonymous]

I accidentally opened a AC9 file in AC10 and then saved. When I try to re-open in in AC9 it gives me the attached error.

What can I do?

[Aaron Bourgoin]

Do you see an .LCK file in the file directory? If so delete it and re-attempt.

[Richard Morrison]

You can also try saving it back to AC9.0 format under "Save As" and selecting the AC9.0 format option.