MP3 reports cannot open file for writing

About two months ago, MP3tag began to refuse the changes I requested for my MP3 files. It instead gave me a message "File D:(whatever)...songtitle...
cannot be opened for writing.

I am using Mp3tag v2.94.

Any ideas on a fix?
Thanks,
RJSully

What changed 2 months ago?
Who is the owner of the files? (it is not enough to be Administrator)
Are the files OK? See e.g. How to check files for errors?

I don't recall anything unusual. I think I upgraded to a more recent version of MP3tag.
The files seem fine in that they play audio OK.

The Administrator angle is interesting. from time to time I have been getting notices from Windows regarding administrator status.

I see that that the MP3Tag community has recommendations to check for Mp3 file errors. I will try them out and report back.

Thanks for the response, Florian.

Rick

Updating MP3tag hardly ever leads to unwritable files.
Files are not necessarily OK if something can be heard.
What happens if you move one of the files ot a completely different folder, e.g. documents? Can you modify the tags there?