When you mapped the drive using afscreds.exe you specified a "submount" name.
Are you able to access the submount when you map via NET USE or the Explorer Shell?
NET USE X: \\AFS\submount
smime.p7s
Description: S/MIME Cryptographic Signature
When you mapped the drive using afscreds.exe you specified a "submount" name.
NET USE X: \\AFS\submount
smime.p7s
Description: S/MIME Cryptographic Signature