Hook denied creation of account - Your WordPress Toolkit license allows 0 Deluxe accounts

Symptoms

When creating an account, you might see the following error in WHM:

Account Creation Status: failed
Hook denied creation of account: Failed to handle event Accounts::Create. Error: Action is blocked: Your WordPress Toolkit license allows 0 Deluxe accounts, and this limit would be breached if you continue. Upgrade your WordPress Toolkit license to have more Deluxe accounts

Description 

This error is caused by the "WordPress Toolkit Deluxe" feature being enabled in the feature list that is selected (usually, default), and the server either not having a deluxe license or already using the maximum amount of deluxe accounts.

Workaround

If you wish to use WordPress Toolkit Deluxe, upgrade Toolkit via WHM.

If not, disable the feature with these steps:

1. Navigate to WHMPackages »Feature Manager »Feature Lists
2. Select the feature list(s) that has the deluxe feature enabled (likely, default)
3. Select "Edit"
4. Uncheck the box for "WordPress Toolkit Deluxe"
5. Click Save

If you already have WordPress Toolkit Deluxe, you may just need to ensure that your license is renewed or up-to-date. If this is the case, please see:

Troubleshooting WordPress Toolkit License Renewal