Lightroom classic file "show in explorer" pops quick error message

And you checked to make sure that a pop under instance is not occurring,. That is to say the message disappeared underneath whatever LrC was showing?

"i get a quick pop-up screen that has an error message that iI cannot read because it disapears too quickly."

Make a full-resolution screen recording (not a phone video):

https://www.descript.com/blog/article/how-to-screen-record-on-windows

Then you should be able to play back the video frame-by-frame with the Windows video player and see what the message says. Post the screen recording here (keep it short, under 47 MB).

Does this happen whether or not File Explorer is already running?