I have a number of cards that won't let me delete pictures from them. I tried sliding that side bar into a different position, and I tried a different computer as well. No luck. I wonder if others experience the same frustration. It's rendering the cards useless for future trail cam use

Yes the bar that locks it is moving when you put it in the computer Angle from the opposite side that it’s on as you insert
It should be pushed forward to unlock it

Format the card in the camera. I always format the card when I place a camera in the field. If you're not sure how to do it, just ask

I had the same problem tried a different computer also still didnt work. I found out if I put the card back in the camera and used the delete function on the camera it would delete the pictures and my problem was solved. Found out that was the only way you could delete photos you had to use the camera not the computer. Get your owners manual out and go thru the steps to delete photos and see if that works for ya.

Like others have said, try reformatting your SD card. You can use your computer if you go to my computer, right click on the card icon, and hit format

I have had this happen 100's of times. It's always the lock moving backwards when inserting. Sd cards are used for tons of things besides trail cams. I always format on the computer when I open them . Some of my cards are pushing 15 years old. Just opened new pack in august of 16 gig. When they get some age on them the lock moves too easily.

Some PCs have a SD card manager option right on the PC. Do a web search and the directions should come up.

Simple as that!