Hi, I am having the same problem with two Macs with the same configuration when upgrading from 4.1 to 5.1.
Configuration:
Mac Pro 2009 4.1 - MP41.0081.B07
2x 2.6 Xeon
32 GB DDR3 1333 (working at 1066)
1TB SATA ssd
I am following this guide here: https://thehouseofmoth.com/turning-a-2009-41-mac-pro-into-a-2010-2012-51-mac-pro-2021-edition/
The problem is that, with both machines, everything appears to be regular but on reboot, after the sound and flashing of the Front Led, the Macs reboot regularly by booting Mac OS.
I tried to have a look here on the forum but still could not solve the problem.
Configuration:
Mac Pro 2009 4.1 - MP41.0081.B07
2x 2.6 Xeon
32 GB DDR3 1333 (working at 1066)
1TB SATA ssd
I am following this guide here: https://thehouseofmoth.com/turning-a-2009-41-mac-pro-into-a-2010-2012-51-mac-pro-2021-edition/
The problem is that, with both machines, everything appears to be regular but on reboot, after the sound and flashing of the Front Led, the Macs reboot regularly by booting Mac OS.
I tried to have a look here on the forum but still could not solve the problem.