The card was formatted within android, and works OK with windows. I have used windows "check for bad sectors" and nothing was reported on the Android-formatted card.. Unfortunately there does not seem to be a utility for android to check sd card physical blocks/sectors whatever (unless you are rooted).
I have a PNY 128 GB SD Card formatted as external in Marshmallow--in an HTC One M8. I have a directory of music on a PC. Recently the size of this directory exceeded 59GB (64GB). I keep the SD Card on my phone synced to this directory with SMB Sync or FolderSync ---top rated apps. As soon as the PC directory got bigger than 64 GB, files transferred to the SD Card in the phone were corrupted and Power Amp said "Failed to Play File" I verified that the files were corrupted by comparing MD5 checksums on the SD Card files versus the files on the PC. The SD Card is PNY and can accept more than 64 GB data using Windows and an SD Card reader. Has anyone seen this?