Your addon domain limit of X addon domains has been reached.

Symptoms

When adding an addon domain to a cPanel account, an error similar to the following occurs:

Your addon domain limit of X addon domains has been reached. The addon domain domain.tld was not added.

Description 

This error is returned when an account has reached the addon domain limit configured in the account's package. This can be corrected by increasing the number of addon domains allowed for the package the account is on, upgrading the account to a package that allows more addon domains, or removing unused addon domains from the account.

Workaround

Increase the addon domain limit for the package:

1. Log into WHM as the 'root' user.
2. Navigate to "Home / Packages / Edit a Package."
3. Select the package to edit from the "Package" list.
4. Click the "Edit" button.
5. Change the value of "Max Addon Domains" to the desired value.
6. Click the "Save Changes" button.

Change the account's package:

1. Log into WHM as the 'root' user.
2. Navigate to "Home / Account Functions / Upgrade/Downgrade an Account."
3. Select the account to modify.
4. Select the package on which to place the account.
5. Click the "Upgrade/Downgrade" button.

Remove unneeded domains:

1. Log into the cPanel account.
2. Click on the "Domains" icon in the "Domains" section of cPanel.
3. Click the "Manage" button to the right of the domain to remove.
4. Click the "Remove Domain" button.
5. Click the "Yes, Remove This Domain" button.