When I Try to connect using Netserial I get this message

PCBOARD was unexpected at this time

What does that mean?

Ruben Figueroa aka Zazz
Mystic Prison Board Sysop
telnet://pbmystic.rdfig.net:24
Web: www.rdfig.net

--- Mystic BBS v1.12 A48 2022/07/15 (Windows/32)
* Origin: Mystic Prison*Mesquite Tx*pbmystic.rdfig.net:24 (1:124/5014)