Megadap released new firmware updates to resolve the compatibility issue with the latest Nikon Z8 firmware update version 3.0:
Update: Fringer has also released a firmware update, which can be found at the bottom of this page.
Thanks to Dariusz Breś and everyone else who sent that in.
Viltrox also warns: don’t update Nikon cameras’ firmware with third-party lenses attached
Some Tamron lenses may not be fully compatible with the latest Nikon Z8 firmware update 3.0