No reading my new SD cards

I have several cameras in different businesses, however I have over half that are now saying they can’t read my micro SD. I have removed the cards, bought new cards confirmed they aren’t full however still says no SC Card found.

Also I have several different versions of the cameras can you tell me why I don’t show the playback option on some of the cameras?

Thanks Denise

Do you have record to the SD turned on for all your cams, events only or continuous recording?
Are you trying to playback the SD from live view or the events page?
Do you get this message or is the playback button grayed out on some of the cameras.

I had this problem when started to use one of the cameras, don’t remember if it is v3 or v4, but later I fixed it myself…