Hi dctung,
I can imagine multiple scenarios where a financial year can be cancelled unintentionally. Currently, the program does not allow undoing this process. This is why there is a prompt to create a backup before closing a financial year. If you created a backup in the process, you can restore it and use the file as it was in the previous financial year. If not, you can still record transactions from the previous financial year. However, reporting periods on some reports may already be fixed for the next financial year.
If you have any other questions regarding this, feel free to let us know.
Thanks,
Genreve