The voucher sequence determines the next number for a voucher. If there are issues, you may need to fix the sequence.
To generate the voucher sequence:
Make sure to close all the databases.
Open UBS, Admin, Administrator Settings, and System Settings.
At Country Setting, Click to Setup and Advance Setting.
Ensure to tick the last option, Voucher Sequence Follow Batch No, and OK.
Open the database.
Go to Report, General, and select Generate Voucher Sequence.
Select Ok and Yes to generate.
Click Exit once done.
The voucher and batch number will be in sequence.