The other night I had my Veeam box decide it was not going to backup my VM’s. This, naturally, is unacceptable behavior! The error I was getting was the following (I cut out all the junk from my environment):
Processing <VMName> Error: An unexpected network error occurred. Failed to write data to the file <StorageUNC>.vbk]. Failed to download disk. Shared memory connection was closed. Failed to upload disk. Agent failed to process method {DataTransfer.SyncDisk}.
Before you jump to the obvious, there were no network related issues. I did some digging and I found the solution! I apologize to the random blog that I found the solution from, I have since closed the tab and lost the link. Anywho, the following directory needs to be empty:
C:\Windows\TEMP\vmware-SYSTEM
I had a log file left in the directory. Cleared it out, bounced the box (because why not?), and kicked off a backup of all my VM’s which completed without issue.