This is happening to me:
1. Opened existing file
2. Go to organize and delete one or two pages as necessary
3. Click the x so Adobe asks if I want to save, hit yes OR Choose file save to save the file
4. Adobe saves the file with a temp file name like A9rwqngxivbermkgo.tmp.pdf
5. Adobe throws an error message "The document could not be saved. Cannot save to this filename. Please save the file with a different document name or in a different folder.
6. I click ok and then have to do a save as in order to save the file as the same name.
7. Then Adobe saves it.

This happens every time I open an existing file and delete a page or two and want to save the file.