"Error: Cannot invoke method startDeviceUpdate() on null object" when updating ZWave device firmware

I am trying to upgrade the firmware on multuple iBlinds v3 devices. A couple of them have updated correctly but I have not been able to update the rest. If the upload finishes, I get this error:

I have tried 3 different drivers: built in, community driver and iblinds 3.1 from iBlinds and none of them helped. I have been using the Community Driver in daily usage because the built in one doesn't work with the shades dashboard widget. I am upgrading them from 3.01 to 3.03.

I am not sure what else to try. Any suggestions?

PS. I didn't see anything in the linked logs.