Payment update error - even in VM 3.6.4 10187

[Anna_Bolika]

Hi Folks

I'm on J! 3.9.12 and VM 3.6.4 10187

I recently did some changes in our own payment plugins we are selling, and want to test the update.
But the update don't work, it throws a error in the J!-Backend: Call to a member function load() on null

The updater try to load the plugin to fire a event on it in administrator/components/com_installer/models/update.php:611
That invokes the plugin's __contruct() method (and all it's parent's) and that lead's to the error in ../administrator/components/com_virtuemart/plugins/vmplugin.php:131 where there the __construct() method tries to load the language.

Trace stack was/is:
1    ()                                           JROOT\administrator\components\com_virtuemart\plugins\vmplugin.php:131
2    vmPlugin::loadJLang()                   JROOT\administrator\components\com_virtuemart\plugins\vmplugin.php:108
3    vmPlugin->loadJLangThis()                JROOT\administrator\components\com_virtuemart\plugins\vmplugin.php:78
4    vmPlugin->__construct()                JROOT\administrator\components\com_virtuemart\plugins\vmpsplugin.php:28
5    vmPSPlugin->__construct()                JROOT\plugins\vmpayment\postfinance\postfinance.php:36
6    plgVmPaymentPostfinance->__construct()             JROOT\libraries\src\Plugin\PluginHelper.php:283
7    Joomla\CMS\Plugin\PluginHelper::import()               JROOT\libraries\src\Plugin\PluginHelper.php:182
8    Joomla\CMS\Plugin\PluginHelper::importPlugin()          JROOT\administrator\components\com_installer\models\update.php:611
9    InstallerModelUpdate->preparePreUpdate()          JROOT\administrator\components\com_installer\models\update.php:359
10    InstallerModelUpdate->update()                JROOT\administrator\components\com_installer\controllers\update.php:44
11    InstallerControllerUpdate->update()             JROOT\libraries\src\MVC\Controller\BaseController.php:710
12    Joomla\CMS\MVC\Controller\BaseController->execute()       JROOT\administrator\components\com_installer\installer.php:19
13    require_once()                      JROOT\libraries\src\Component\ComponentHelper.php:402
14    Joomla\CMS\Component\ComponentHelper::executeComponent()    JROOT\libraries\src\Component\ComponentHelper.php:377
15    Joomla\CMS\Component\ComponentHelper::renderComponent()    JROOT\libraries\src\Application\AdministratorApplication.php:101
16    Joomla\CMS\Application\AdministratorApplication->dispatch()    JROOT\libraries\src\Application\AdministratorApplication.php:159
17    Joomla\CMS\Application\AdministratorApplication->doExecute()    JROOT\libraries\src\Application\CMSApplication.php:196
18    Joomla\CMS\Application\CMSApplication->execute()       JROOT\administrator\index.php:51

Can someone lead me to the dev-conversation as statet in
http://virtuemart.net/news/496-bugfix-release-3-6-4-outdated-payment-plugins-work-again

I checked the __contruct() methods from the other (core-) payments, but see nothing that I should change in my own contructors.

Cheers
Roger