Diagnosis
At least one of the account number range limits has no input. Accountnumbers must not have a zero length (0) therefore this entry isinvalid.

Example
Lower limit 0000000
Upper limit 999999999
This states that an account number must be between 7 and 9 digits longand within the range specified.

What to do
Use the ACB user manual specification Appendix E to specify the correctrange.