File attribute mismatch-Open failed. Mismatch in LRECL or BLOCKSIZE or RECFM between your COBOL pgm & the JCL (or the dataset label).
A conflict has been detected between the actual file attributes and the attributes specified for the file in the program. This is usually caused by a conflict with record-length, key-length, key-position or file organization. Other possible causes are: 1. Alternate indexes are incorrectly defined (Key length or position, duplicates or sparse parameters). 2. The Recording Mode is Variable or Fixed or not defined the same as when the file was created. 3. For files with variable-length records the minimum and maximum record lengths for the actual file may not match the minimum and maximum record lengths used by the program.