Failure
TypeError: current(): Argument #1 ($array) must be of type array, string given in current() (line 159 of root-dir ...is the directory, where your Drupal website files and folders are stored (core, modules, sites, themes, .htaccess etc.), if you follow the recommended project structure it's the web folder of your project directory, i.e. /var/www/html/wisski.com/web, or C:/xampp/htdocs/wisski.com/web. \modules\contrib\wisski\wisski_salz\src\Query\WisskiQueryDelegator.php)
Solution
Navigate to Manage Configuration WissKI Configuration (WissKI section) and check Do you want to use only main bundles for display? and Do you want to use views for navigation?. Click Save.
Go to Manage Configuration Pathbuilders (WissKI section) and recreate bundles for every pathbuilder ... is the place where you define the WissKI structure, configure groups and fields and tell WissKI to which adapter it should send the queries. You can export/import your pathbuilder setup. The administrative name of a pathbuilder could something like Collection and Collection Items or Named Entities. by clicking on Edit in the Operations column and click Save and generate bundles and fields.