In this post, you’ll learn about the COBOL runtime Error Code 100 and the reason why you are receiving it
COBOL Error Code :
100
Reason for this Error in COBOL
Invalid file operation (Fatal) -You have tried a file operation which violates a general rule of COBOL in some way. The most likely cause of this error is that you have tried a rewrite on a sequential file opened I-O, or on a relative file with access mode sequential also opened I-O, without preceding it with a successful read NEXT. -Recode your program to ensure that the REWRITE statement in error is preceded by a read NEXT.