New install, most of old tags not showing

So brand new install of 2.78 because i needed to tag about 20 new files and didn't want to use iTunes and could not remember what i had used before that. Anyhow out of about 1400 title loaded only about 100 are showing tag info and cover art. They are all tagged and showing fine in Windows 7 and iTunes though. I checked options tags and the read are showing v1, v2, and APE. Looked through the forums no luck on how to fix. Not sure how to tell what kind of tags they are but I was pretty sure they were v2 tags.

Check what kind of tag versions are in the files. In a default install, you should see a column (more to the right of the files list) that shows the tag versions.
If the files have APE tags, it could be that these tags are empty and that the real information is stored in the V2 and V1 tags.
As a remedy, you could switch off the reading of APE tags and see if more information pops up.

If this is the case, you should remove the APE tags.

Yep that fixed it! Whats an APE tag and how do i remove it without breaking the other ones? Thanks for the assist.

I think that mainly replaygain information is stored in APE tags (although it could just as well be saved in ID3 tags).
In MP3tag there is a hierarchy for reading tags: APE>V2>V1
So APE wins.

To get rid of the APE tags:
Set the Tools>Options>Mpeg so that APE tags get deleted (no read or write).
Filter the files with %_tag% HAS APE

Select a set of files.
Right-click on the selected files.
Cut the tags.
Paste the tags.
Done (for this set of files).
Refresh the filter: press F3 twice
Now the treated files should not be displayed in the list any more.

Even older boffins in the forum claim that simply saving the tags again (ctrl-s) would re-write them and therefore remove unwanted tag versions. You may as well try this approach. I am not sure that it works.