Not able to add new items without selecting a resource template after activating LDS-module

[Xentropics]

Issue

When I want to add a 'freeform' item without selecting a resource template Omeka S encounters an error. After deactivating the LinkedDataSets-module, it works as expected (i.e. an item is added).

Screenshot to replicate:

Error + stack trace:

Error
Call to a member function label() on null

Details:

Error: Call to a member function label() on null in /var/www/html/modules/LinkedDataSets/Module.php:139
Stack trace:
#0 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(319): LinkedDataSets\Module->dispatchJobs(Object(Laminas\EventManager\Event))
#1 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(171): Laminas\EventManager\EventManager->triggerListeners(Object(Laminas\EventManager\Event))
#2 /var/www/html/application/src/Db/Event/Subscriber/Entity.php(117): Laminas\EventManager\EventManager->triggerEvent(Object(Laminas\EventManager\Event))
#3 /var/www/html/application/src/Db/Event/Subscriber/Entity.php(78): Omeka\Db\Event\Subscriber\Entity->trigger('entity.persist....', Object(Doctrine\ORM\Event\LifecycleEventArgs))
#4 /var/www/html/vendor/doctrine/event-manager/lib/Doctrine/Common/EventManager.php(41): Omeka\Db\Event\Subscriber\Entity->postPersist(Object(Doctrine\ORM\Event\LifecycleEventArgs))
#5 /var/www/html/vendor/doctrine/orm/lib/Doctrine/ORM/Event/ListenersInvoker.php(99): Doctrine\Common\EventManager->dispatchEvent('postPersist', Object(Doctrine\ORM\Event\LifecycleEventArgs))
#6 /var/www/html/vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php(1158): Doctrine\ORM\Event\ListenersInvoker->invoke(Object(Doctrine\ORM\Mapping\ClassMetadata), 'postPersist', Object(Omeka\Entity\Item), Object(Doctrine\ORM\Event\LifecycleEventArgs), 4)
#7 /var/www/html/vendor/doctrine/orm/lib/Doctrine/ORM/UnitOfWork.php(425): Doctrine\ORM\UnitOfWork->executeInserts(Object(Doctrine\ORM\Mapping\ClassMetadata))
#8 /var/www/html/vendor/doctrine/orm/lib/Doctrine/ORM/EntityManager.php(392): Doctrine\ORM\UnitOfWork->commit(NULL)
#9 /var/www/html/application/src/Api/Adapter/AbstractEntityAdapter.php(349): Doctrine\ORM\EntityManager->flush()
#10 /var/www/html/application/src/Api/Manager.php(224): Omeka\Api\Adapter\AbstractEntityAdapter->create(Object(Omeka\Api\Request))
#11 /var/www/html/application/src/Api/Manager.php(78): Omeka\Api\Manager->execute(Object(Omeka\Api\Request))
#12 /var/www/html/application/src/Mvc/Controller/Plugin/Api.php(99): Omeka\Api\Manager->create('items', Array, Array, Array)
#13 /var/www/html/application/src/Controller/Admin/ItemController.php(215): Omeka\Mvc\Controller\Plugin\Api->create('items', Array, Array)
#14 /var/www/html/vendor/laminas/laminas-mvc/src/Controller/AbstractActionController.php(71): Omeka\Controller\Admin\ItemController->addAction()
#15 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(319): Laminas\Mvc\Controller\AbstractActionController->onDispatch(Object(Laminas\Mvc\MvcEvent))
#16 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(179): Laminas\EventManager\EventManager->triggerListeners(Object(Laminas\Mvc\MvcEvent), Object(Closure))
#17 /var/www/html/vendor/laminas/laminas-mvc/src/Controller/AbstractController.php(97): Laminas\EventManager\EventManager->triggerEventUntil(Object(Closure), Object(Laminas\Mvc\MvcEvent))
#18 /var/www/html/vendor/laminas/laminas-mvc/src/DispatchListener.php(132): Laminas\Mvc\Controller\AbstractController->dispatch(Object(Laminas\Http\PhpEnvironment\Request), Object(Laminas\Http\PhpEnvironment\Response))
#19 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(319): Laminas\Mvc\DispatchListener->onDispatch(Object(Laminas\Mvc\MvcEvent))
#20 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(179): Laminas\EventManager\EventManager->triggerListeners(Object(Laminas\Mvc\MvcEvent), Object(Closure))
#21 /var/www/html/vendor/laminas/laminas-mvc/src/Application.php(325): Laminas\EventManager\EventManager->triggerEventUntil(Object(Closure), Object(Laminas\Mvc\MvcEvent))
#22 /var/www/html/index.php(21): Laminas\Mvc\Application->run()
#23 {main}

Contextual information:

Omeka version: tested on 4.0.1 and 4.0.4

Installed modules:

  "modules": [
    {
      "name": "IiifServer",
      "version": "3.6.14",
      "zipUrl": "https://github.com/Daniel-KM/Omeka-S-module-IiifServer/releases/download/${version}/IiifServer-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name": "ImageServer",
      "version": "3.6.14",
      "zipUrl": "https://github.com/Daniel-KM/Omeka-S-module-ImageServer/releases/download/${version}/ImageServer-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name": "ValueSuggest",
      "version": "1.16.1",
      "zipUrl": "https://github.com/omeka-s-modules/ValueSuggest/releases/download/v${version}/ValueSuggest-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name": "NdeTermennetwerk",
      "version": "1.1.0",
      "zipUrl": "https://github.com/omeka-s-modules/NdeTermennetwerk/releases/download/v${version}/NdeTermennetwerk-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"AdvancedResourceTemplate",
      "version": "3.4.26",
      "zipUrl": "https://github.com/Daniel-KM/Omeka-s-module-AdvancedResourceTemplate/releases/download/${version}/AdvancedResourceTemplate-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"CSVImport",
      "version": "2.5.0",
      "zipUrl": "https://github.com/omeka-s-modules/CSVImport/releases/download/v${version}/CSVImport-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"FacetedBrowse",
      "version": "1.3.1",
      "zipUrl": "https://github.com/omeka-s-modules/FacetedBrowse/releases/download/v${version}/FacetedBrowse-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"CustomVocab",
      "version": "2.0.2",
      "zipUrl": "https://github.com/omeka-s-modules/CustomVocab/releases/download/v${version}/CustomVocab-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"NumericDataTypes",
      "version": "1.11.3",
      "zipUrl": "https://github.com/omeka-s-modules/NumericDataTypes/releases/download/v${version}/NumericDataTypes-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },

    {
      "name":"LinkedDataSets",
      "version": "0.1",
      "zipUrl": "https://github.com/netwerk-digitaal-erfgoed/Omeka-S-Module-LinkedDataSets/releases/download/v${version}/LinkedDataSets-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"UriDereferencer",
      "version": "1.4.0",
      "zipUrl": "https://github.com/omeka-s-modules/UriDereferencer/releases/download/v${version}/UriDereferencer-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name":"Ark",
      "version": "3.5.13.4",
      "zipUrl": "https://gitlab.com/Daniel-KM/Omeka-S-module-Ark/-/archive/${version}/Omeka-S-module-Ark-${version}.zip",
      "install": false,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    },
    {
      "name": "ServerUrlOverride",
      "version": "1.0.0",
      "zipUrl": "https://github.com/zerocrates/ServerUrlOverride/releases/download/v${version}/ServerUrlOverride-${version}.zip",
      "install": true,
      "config": false,
      "configForm": { "url": "", "formData": [] }
    }
 ]