I would say that newer Grafana binaries are built with newer Golang 1.21+, which doesn’t support your old Windows 2008r2 anymore (it is 4 years after end of extended support - why you are using it anyway 
).
As announced in the Go 1.20 release notes, Go 1.21 requires at least Windows 10 or Windows Server 2016; support for previous versions has been discontinued.
So if you need it, then build own Grafana binaries with Golang 1.20.14.