After downloading a password-protected document (with password protection but authorization for form processing and saving) can only save once.

When trying to save the document a second time (also under a different name), the error message appears:
"The document could not be saved.
The file is either read-only or used by another user.
Save the document under a different name or in a different folder. "

Unfortunately, the document can not be saved under a different name and / or folder.