Thanks for clarifying the points.

Changing the folder to save a file may solve this issue. Because this alert appears if you do not have a security permission on the folder, where you want to save your file, to write or if it is read-only.

So please make sure that you have security permission on the folder, where to save a file, to write and then try again.

Hope this helps. If you are still unable to save a file, please let us know. Thanks.

Best regards,
Satomi