Hmm. Yeah, it's gonna be hard to track down a cause without knowing when it happened. Is there any correlation between the missing tags and the tracks you edited for spelling? Unless there is, I think we can eliminate that as a cause.
I don't remember which were the tracks or tags with spelling mistakes unfortunately. But I think I might have done it with boroda's tool (that's the only one with search and replace, right?) (Not to blame, just surfing possibilities. Also see below regarding modified dates).
One thing that gets me in trouble from time to time is MB's tendency to grab from the top down to whatever track I select, when I shift-select in a node or playlist I just opened. Are these tracks with missing tags all clustered together in your library or anything like that?
How can I know that? Because my order is now on "tempo" in my library and of course then they are grouped together. And it might have been that I did a multiselect in that current order, but I can't know.
Although the modified dates would all be the same then, wouldn't they? And they are not.
"Data modified" from my 1500 "tag-damaged" tracks range from 2004 upto 2014 without any big groups, quite divided. Which, if you think about it, I find very strange on itself. Does MB or MB addons sometimes NOT modify the date when changing tags?
Also, a long shot, but have you used Windows Media Player for anything at all?
Sometimes Windows Media Player opens when I click on some files that weren't linked to open with MB, but I then close it immediately. I doubt it would do such a thing in such a short time without extra commands, would it? (Does W.M.P. edit tags without modifiyng the date MB uses as "modified date" ?)
I'm just reporting there is something very wrong with Musicbee. I am sorry for your trouble, but that's a big statement, isn't it? Yet, I don't see any evidence from your posts and can't think of any way MB could do that without the user's knowledge. Let us know if you find some.
Yeah, it was. I don't see what else could have done it, besides MB and/or MB addons, but you can interpret it as "might very well be" in stead of "is". I will report if I find anything, but I think it will be Don Quichote calibre...
I'd first check file modification date of files and try to figure out what kind of changes were made to them when and how.