SAP Message C1157 - Check table & has too many key fields

Diagnosis
You have entered a check table that has more than one key field,possibly because an existing client is not taken into account.
Check tables with more than one key field are not supported. However,if you enter a function module for checking values, you can refer toany check table in your own coding.

Procedure
Please choose a check table that contains exactly one key field and aclient, if required.