Problem with "open/checkout document'

PDM 20009--- When trying to open/checkout a file from the vault, I receive this error message" Error Retrieving "###" From Server"  Logged in as administrator--file exists in vualt and can be openned with "Check in from disk".  Also, after using "check in from disk" and trying to recheck in I receive "Vault Error 50"

please help--thanks

SolidworksWorkgroup Pdm