When deactivating an account in QuickBooks Desktop, you need to make sure there are no pending transactions and the last connection has been completed. Since your account is already updated, you can re-sort your list to go back to its default order and remove the error message like that you've encountered. But before doing so, you'll have to make sure you create a backup of your company files. Further, you can proceed with the below-given steps:
Go to the Lists menu and select Chart of Accounts.
Click the Include Inactive checkbox. If it's grayed out, there are no inactive names.
Go to the View menu, then select Re-sort List.
Close and reopen your company file.
If you couldn’t reactivate the bank account and are still stuck with QuickBooks Online error code 101, then we would suggest you to take our experts assistance.