Take the compile listing for the program that has either OFFSET or LIST option selected. Use the OFFSET or LIST output to determine which line of the COBOL program has the error based on the offset in the error message. This will tell you the variable or variables involved. One of them has an invalid numeric value, hence the S0C7 abend.
LINE # HEXLOC VERB LINE # HEXLOC VERB
003172 00168E PERFORM 003185 00168E OPEN
003187 0016BA MOVE 003189 0016C4 MOVE
007278 0016D0 DISPLAY 007279 0016DA DISPLAY
007282 0016EE DISPLAY 007283 0016F8 DISPLAY