function-name PDS config-DD-name:member-name RECFM not F or FB, cannot process
Error message issued by VNCRXF12, the GETCFG function that reads agent configuration files. The function has opened member-name, examined the first record, and determined that it contains a variable-length record header.
In the mesage text, operation=READ. In a standard agent installation, config-DD-name:member-name=VNCCFG:VNCCFG00. Or it equals whatever member name the user specified as the first parameter of the OBEYFILE exec.