Call to undefined method JModuleHelper::isAdminMultilang() after updating Joomla 3.8.1 Menus no longer accessible - PayPlans module causing issue

Hi,

I upgraded Joomla to 3.8.1 the other day and was no longer able to access my Administrator menu items. I was getting the error:

Call to undefined method JModuleHelper::isAdminMultilang()

After a few days I have finally found the cause. I added the following code

$class = new ReflectionClass('JModuleHelper');

echo $class->getName() . '

';

echo $class->getFileName() . '

';

die();

to my administrator/templates/isis/index.php which identified a PayPlans module as the culprit. I changed the folder name to see if my menus worked and they did.


The problem is caused by this:
/home/mysite/public_html/plugins/payplans/moduleaccess/moduleaccess/joomla/abstract/j35/module/helper.php

At the moment it is currently disabled, but obviously it must be needed so hopefully there is a solution?

Kind regards

Mel