If you find a copy elsewhere, verify it against the known SHA-256 Hash to ensure it hasn't been tampered with:
cluster1::> security certificate install -type server -vserver cluster-mgmt cluster1::> system manager software upload -package NetAppSysManager-3.1.3.jar cluster1::> system manager start -vserver cluster-mgmt netapp oncommand system manager 3.1.3 download
(Windows/Linux/Mac) File ID: 0123456789 (example) If you find a copy elsewhere, verify it