Keynote 'The document could not be autosaved'

 Question:

　　When I used keynote to edit slides and want to save the modified resutls. However,  it happens.

 

I search it on goolge, however, no ways can solve this issue.

I have tried

　　Method 1: created new files and copy the old file into new files, but failed.

　　Method 2: deleted all slides in the old file, but still cannot save.

 

Finally, I came up with an idea that

1). "File->Export to->.pptx" in keynote

 

 

2). Then you can do anything in 'the exported pptx', such as edit, save ,copy.

3). You can do "File-> Export to-> keynote" for the exported pptx to get .key file IF you want.

 

Solved!

 

By the way, you can use "Revert to" restore the history version in keynote (like the git), this is useful.