Convert - "Filename -Tag" disabled

Newbie here. I used Mp3tag to straighten out several hundred files and this function worked great! But, after I ripped several more CDs using Windows Media Player in Windows 10 to produce 256Kbps audio files, now the [Convert - "Filename -Tag"] is disabled when I go to use it. I can't change the title, artist or any of the metadata fields like I did previously either one at a time or in batches.
The only difference I know of is the older files I was able to work with were mostly 128Kbps and 192Kbps files. I can go back to those files and edit them but not the ones I've just done.

Does anyone know what would keep Mp3tag from updating these files? What am I doing wrong?

You have to select at least on file in the files list.
Then the pattern of the format string has to match the actual filename.
This includes any hypens, blanks, parenthesis and stuff.
So if you show us a real filename and the pattern with which the Converter keeps being disabled, it may be possible to give you some hints which pattern is probably better.

I do select one or more files. I've got it working again. There are some directories from the ripping that seem to give problems - maybe the ones that pre-append the track numbers but I'm not sure.
My "Tag - Filename" is %title% - %artist%
My "Filename - Tag" is %title% - %artist%
They seem to do what I want done correctly most of the time. Occasionally the first song title, artist, album is skipped and replaced with Track 1, unknown artist, unknown album. If I use the Tag - Filename action first, it works better. Once in awhile, it balks at one of the files and refuses to act on it - like it's locked by another process. I have no idea why.
After ripping, my directory looks like:
01 How High The Moon.mp3 the Title, Artist, Album, Year, Track, Genre and sometimes the Composer are shown.

Do you still have the Windows Media Player open? It is known for sometimes blocking files so that other software cannot access it.

Yes, that is true- I run into problems with files being blocked when I was using MPC for a while for audio files when at the same time using Mp3tag

I figured the song title, artist and album not showing up was a Windows Media Player problem. It's easy enough to add the title (from the file name) and album information (from the other files on the album) back in but when the album is a collection and not all the same artist, I've had to go looking a few times. "Shazam" on my cellphone has come to the rescue a few times.

As a newbie, I'm working through the Mp3Tag tutorials Florian Heidenreich is so graciously sending me so I can get up to speed.