sd card error

Android 12 Galaxy S10e. I took several screen recordings using the native function. Moved many to sd card using "files by google" app. moved them separately in groups of 1-3) Some of them are playable, some are not. as pictured, the ones with blank thumbnails are unplayable. they are unplayable...

my Acer Chromebook is not reading a Sandisk image mate 64GB micro sd card that was read before.

My new to me, used nikon coolpix camera is showing sd card errors. Ive tried different cards & tried formatting them all. They work in my other cameras. The coolpix shows me a message "This card cannot be used" And one odd thing is the menu completely skips over the format from camera option...

I've recently purchased a 264gb sd card for my Samsung s20. I had transferred a my videos on to this however now I cannot play any video on my phone or laptop. When I try to play the video it states " Failed to play video, an unknown error has occured" I can see the files and they all have data...