If you use vr-Default main ports - then "tftp put vr vr-Default primary.cfg"
If you use MGMT port of MSM module - then "tftp put vr vr-Mgmt primary.cfg" or do not specify VR.
Also you have to look that you home folder in TFTP server is configured right.
Also you have to look with "ls" command that primary.cfg is present in switch