I had the same problem:

The snapshot location was incorrectly set in the replication properties

the Replication wizard defaults the snapshot directory to something like:

\\ServerName\C$\Program Files\Microsoft SQL Server\MSSQL\ReplData

If you have specified a different directory you will need to set the properties to something like:

\\ServerName\SnapShotDirectory

in Enterprise Manager (EM) you would find this under

-Tools -Replication -Configure Publishing...

select the [Publishers Tab]

select the [...] elipsis of the distrubtion db and set the snapshot folder in there.

That's what worked for me 🙂