JTL WaWi connection / [PrestaShopException] Root category must be an integer value

[telefonino]

Hello,

I need some urgent help. We connected JTL WaWi to Prestashop 1.6.1.9

After working for a while I now experience this error messages when clicking to "articles". Shop is empty so far.

How can this be solved? Am thankful for any hint.

[PrestaShopException]

Root category must be an integer value

at line 212 in file classes/helper/HelperTreeCategories.php

207.     }208. 209.     public function setRootCategory($value)210.     {211.         if (!Validate::isInt($value)) {212.             throw new PrestaShopException('Root category must be an integer value');213.         }214. 215.         $this->_root_category = $value;216.         return $this;217.     }

• HelperTreeCategoriesCore->setRootCategory - [line 2504 - controllers/admin/AdminProductsController.php] - [1 Arguments]
• AdminProductsControllerCore->initContent - [line 189 - classes/controller/Controller.php]
• ControllerCore->run - [line 367 - classes/Dispatcher.php]
• DispatcherCore->dispatch - [line 58 - admin/index.php]