backing up non-stop backup

i'm trying to backup the non-stop backup folder to another computer on my network with MS SyncToy. i get errors about not being able to read three source files because they are in use. they are:

cdp.data
cdp.metadata
cdp45.data

do these errors invalidate the synced backup?
is the synced backup valid at all?

any thoughts are appreciated

rtmxp