Again you can see the error message showing wrong folder. I cannot tell whether it’s due to Windows. The right folder should be “/opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org2.example.com/users/Admin@org2.example.com/msp”. The “/opt/gopath” is being replaced by something very Windows.
Any chance you can have a Ubuntu or Mac environment? Maybe using virtualbox or a cloud instance may help. Meanwhile, please send questions to email@example.com for further communication.