B&R 16 micro SD card backup failing

Hello. I am trying out B&R Free 16, and keep running into the same problem. I am running Windows 10 x64 1607 on a Surface 3 tablet. The surface has a micro-sd flash slot, which I am trying to use to suppliment the very small onboard flash. Backing up the onboard flash C: drive works fine, however any attempt to backup anything FROM the NTFS-formatted micro sd card results in an almost immediate "Base Image - Error encountered: Operation failed. NT specific error 0xc000003a". I have tried full disk/partition/individual file backup of the card, raw and not, all resulting in the same error. The card is fine, chkdsk clean, and readable in other machines (and readable in B&R to select files just fine, just not backup.) I was really hoping B&R would be the backup solution for me with this Surface, because it actually can backup removable media, unlike most other products, just apparently not my removable media.

Any ideas on what I could try would be greatly appreciated.

thanks in advance

Hi,
Please try performing this operation again. This time - using Bootable Recovery Media.

First, go to Home - Recovery Media Builder. Then create a Recovery Media.
Boot from it and perform the operation again.

Will try and revert back.

thank y ou