ResGen : error RG0000: Specific exception: "ArgumentNullException" Message: "Value cannot be null. (Parameter 'format')"

[bradprob]

Hi,
The following error appears when trying to create a strongly-typed resource class by command:
./ResGen/bin/Debug/net8.0/ResGen Resources.resx /str:cs. File Resources.resx is the one from the repository (but providing other .resx files results in the same error).
Error message:

Read in 64 resources from "Resources.resx"
Writing resource file...  Done.
Creating strongly typed resource class "Resources"...  ResGen : error RG0000: Error while writing the output file "Resources.resources"
ResGen : error RG0000: Specific exception: "ArgumentNullException"  Message: "Value cannot be null. (Parameter 'format')"
2 error(s).