TypeError when we're trying to load a client's service with hosting addons

[Stocki]

Dear WHMCS!

We're getting the following error message when we're trying to load an AdminArea Product/Service which has a hosting/product addon (e.g.: admin/clientsservices.php?userid=1234&id=56789):

TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in /path-to-whmcs/vendor/whmcs/whmcs-foundation/lib/Service.php:0
Stack trace:
#0 /path-to-whmcs/vendor/whmcs/whmcs-foundation/lib/Service.php(0): count(NULL)
#1 /path-to-whmcs/admin/clientsservices.php(0): WHMCS\Service->getAddons()
#2 {main}

We think the problem is around the `tbladdons`.`downloads` column, so we've tried to modify it, but none of the queries were successful:

UPDATE tbladdons SET downloads = '0';
UPDATE tbladdons SET downloads = '';
UPDATE tbladdons SET downloads = '[]';
UPDATE tbladdons SET downloads = ',';

We're using the latest WHMCS 8.7.2 (General Release) with PHP 8.1

Thank you in advance if you can help to solve the problem!

Br,
Richard

[Stocki]

It seems, I've solved the mystery.

Someone has removed an old Product Addon (Configuration » System Settings » Product Addons), but the Hosting Addons were not deleted.

I've created a MySQL query to find the affected Hosting Addon records:

SELECT
	tblhostingaddons.*
FROM tblhostingaddons
LEFT JOIN tbladdons ON tblhostingaddons.addonid = tbladdons.id
WHERE tblhostingaddons.addonid > 0 AND tbladdons.id IS NULL

After backing up (exporting) these rows, I've deleted them:

DELETE
	tblhostingaddons
FROM tblhostingaddons
LEFT JOIN tbladdons ON tblhostingaddons.addonid = tbladdons.id
WHERE tblhostingaddons.addonid > 0 AND tbladdons.id IS NULL

The TypeError message is gone.

I hope this helps someone.