Oracle Message PCC-02370 - An EXEC TOOLS MESSAGE host variable is not type char

ERRORAn EXEC TOOLS MESSAGE host variable is not type char
CAUSEf a host variable is used to define a context name in an EXEC TOOLS GET CONTEXT or EXEC TOOLS SET CONTEXT statement, that host variable must be of a character type.
ACTIONDeclare the message to a host variable of a char type.