https://devzone.nordicsemi.com/f/nordic-q-a/78649/issue-upgrading-the-firmware-1-3-0-via-mcubootI&#39;ve upgraded several Thingy91 boards successfully with the latest firmware and have ran into an issue with another Thingy91 that I&#39;ve purchased. Here is the error when I attempt to upgrade the firmware: Modem DFU failed with error: Error: Error occureden-USTelligent Community 13Thu, 19 Aug 2021 11:45:02 GMThttps://devzone.nordicsemi.com/thread/325711?ContentTypeID=1Thu, 19 Aug 2021 11:45:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3e51de1c-5fda-44fd-9652-acb8ab0189f9Heidi<p>Hi!</p> <p></p> <p>1. What OS are you using (please include the version)?</p> <p>2. What Thingy:91 version do you have (this should say on the white sticker on the PCB under &quot;PCA20035&quot;)?</p> <p>3. Did you make sure to put the device in serial recovery mode (pressing SW3/SW4 while turning the device on) before updating?</p> <p></p> <p></p> <p>Best regards,</p> <p>Heidi</p><div style="clear:both;"></div>