Can not create Snapshot

Hi,

When I try and create a snapshot using vSphere client  I get an error "File <unspecified filename> was not found."

Can anyone please suggest where I can I get some more detali on the error or what my problem might be?

On the host I am running VMware ESXi, 5.0.0, 623860.

I have disk space avaiable and other snapshots work on other guests.

Thanks in advance,

Ashley