What is the error in this class diagram?

Question

@startuml

class /IDV0/CO_GENERIC_XMLTICKET_SER { 

}

CL_PROXY_CLIENT <|-- /IDV0/CO_GENERIC_XMLTICKET_SER

@enduml

Answer 1

It's very unusual to put slashes in class name, so some features may react strangely.

In you case, you case use quotes:

@startuml
class /IDV0/CO_GENERIC_XMLTICKET_SER {
}
CL_PROXY_CLIENT <|-- "/IDV0/CO_GENERIC_XMLTICKET_SER"
@enduml

Tell us if you find other issues!

Thanks

Answer 2

Or

@startuml

class "/IDV0/CO_GENERIC_XMLTICKET_SER" as CGX { 

}

CL_PROXY_CLIENT <|-- CGX

@enduml