Uno R4 Minima upload error 74

[Perehama]

It has been posted elsewhere on the forum a few times, so I take no credit for this response. I have no experience with this myself.

@the2ndtierney

I had this issue but when i ran

C:....\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.1\drivers\dpinst-amd64.exe as an administrator I was able to upload sketches.

Hope this helps and thanks @ubidefeo and extended arduino team for this cool microcontroller.