System Cannot Open File Error

[baileyphil]

Morning All

Was wondering if somebody could help me out, got Backupassist V6.2.4 installed on a SBS 2011 server, when the backup runs it fails at the point of "backup E:\" which is the local E drive on the machine, now it runs though the other options of Check Selections, Check Destination, Perform VSS Snapshot, Perform Exchange Consistency Check, without any issues, just when it gets to "Backup E:\" it always fails with the following errors

BA953 Volume Shadow Copy Error 0x800423f3 - writer error: retry-able
Volume Shadow Copy Error 0x800423f0 - writer error: inconsistent snapshot

Then i get a long list of files that are similar to the following in the log file

Writing: (4) The system cannot open the file
... (\\192.168.15.26\backup\Thursday\E\etc\Accounts\REPORTS\Invoice\Sales
... by Analysis Code Reports\IP_ANAL1.SRT)

The internal IP of the NAS device im backing up to is 192.168.15.26

Anyone come across this before, and if so could they help me out?

Many Thanks

Phil