I have ran into this error in my snapshot monitor twice and found nothing on Google, so I thought I would contribute my solution here.
The situation was that I right clicked and deleted all subscribers. I tried to create a new snapshot and it gets to ~98% and aborts with the error.
First of all, you can get a more detailed error message from the Replication Monitor (Right click publication -> Replication Monitor). Look at the snapshot agent and you should be able to get the actual error.
I was able to fix this issue by right clicking the publisher and selecting "Reinitialize all subscriptions" even though there aren't any.