X374: Stored procedure ProcName received a null value for parameter number.

Verify that the LINKAGE column in the SYSIBM.SYSPROCEDURES table correctly specifies whether ProcName can accept null values.

• If ProcName can accept null values, set the LINKAGE value to N.
• If ProcName cannot accept null values, make sure the LINKAGE value is blank. Then correct your CALL statement so that it passes a non-null value for parameter number.