Still seeing "unknown Go version

I am trying to call "go run github.com/rsc/goversion -crypto /tmp/myfile" I get:
/tmp/myfile unknown Go version. This file has been compiled recently. 

When I use an older version this /tmp/myfile it works.

If I run "go version" I get: go version go1.16.4 linux/amd64,    (Ubuntu 7.4.0 and Centos), this seems to the latest version.

Can you please check.