"Failed to delete" message when deleting files from SD card I use smartphone with Android version 5.1.1 Whenever I try to delete files (videos, images, ebooks, etc) from my SD card I get the "Failed to delete" message. I looked for the solution to the problem online but didn't find the matching. What I tried was I unmounted my SD card and mounted it to my PC. Then I ran cmd as administrator and tried these commands in order: 

diskpart 
list disk
select disk 1 (which pointed to my SD card)
attribut disk clear readonly


It didn't work out.  

What do you suggest to do?
It's a very common problem for less reputed SD cards. It can be fixed by doing a full format on the SD card. (Not a quick format because it doesn't check for bad sectors or data redundancy errors). Don't forget to keep a backup before formatting.