If you receive any error when deleting templates associated with your WhatsApp Business account, it is because Meta would’ve disabled your business account, or the partnership with Zoho has been removed.
It is recommended that you check whether your business account is active in the Meta Business Suite. To do this:
You can view if your account has been disabled by Meta under Business Information. If your account is disabled, you can reach Meta and get it enabled again.
You can navigate to the Partners tab to check if Meta has canceled the partnership with Zoho for that business account.
Books
Online accounting software
for small businesses.