PS C:\Users\minec\Downloads\tutorial-mod-template-1.20.1> .\/gradlew genSources
> Configure project :
Fabric Loom: 1.6.11
> Task :genSourcesWithCfr FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':genSourcesWithCfr'.
> Failed to decompile, java.lang.RuntimeException: Failed to rebuild input jars, java.nio.file.ClosedFileSystemException: null
* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.
BUILD FAILED in 12s
1 actionable task: 1 executed
In your screenshot you miss the . that you need for PowerShell in the beginning of the command.
But overall, this is most probably since issue with some plugin you use, so you should probably ask the maintainers of said plugin for help. The build scan could probably tell you where the problem is coming from exactly.