Snapshot failed, insufficient space VSS Error


I was trying to protect a machine that was previously protected by another core a few months back that was shut down, now trying to protect with a new core. but it is failing with a VSS error that there is insufficient space. The C drive has plenty of space it is only Windows Server. Not sure if it is regarding the system reserve partition. It is on agent 6.1. I was thinking a reboot may help, or I can update the agent to 6.4 to try and protect the machine again.