MCBoot DFU fails

[JoelRietz]

This happens when I try to do DFU on my Thingy 91. I am trying to download the file thingy91_item_dfu_2020-04-29 file and the same also happens when I try update the modem. Any suggestions what the issue could be? I've seen other peopl having similar issues in the forum. Really need this to work...

[JoelRietz]

Yes

[matt.heins]

Has the 9160 been programmed via SWD with a program containing MCUBoot? 

[JoelRietz]

Nope, I just picked it out of the box and I try to program it using USB now for the first time.