Change the account class so that it uses just the UPDATE ON option of the repository directive and add the as "base" to the CLASS phrase as shown below:
$set repository "UPDATE ON"
CLASS-ID. Account INHERITS Base.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
REPOSITORY.
CLASS Base as "base".
Do not use the repository directive for the bankmain.cbl at all.
This worked fine for me...
Thanks.