Thanks for the great module. However, when we want to use it with the ECA module, it gives an error as "Source fields field is required" (even though source field is selected) and the following error message appears in the log.
Warning: Array to string conversion in Drupal\eca_modeller_bpmn\ModellerBpmnBase->prepareConfigFields() (line 776 of /opt/drupal/web/modules/contrib/eca/modules/modeller_bpmn/src/ModellerBpmnBase.php)
#0 /opt/drupal/web/core/includes/bootstrap.inc(164): _drupal_error_handler_real(2, 'Array to string...', '/opt/drupal/web...', 776)
#1 /opt/drupal/web/modules/contrib/eca/modules/modeller_bpmn/src/ModellerBpmnBase.php(776): _drupal_error_handler(2, 'Array to string...', '/opt/drupal/web...', 776)
#2 /opt/drupal/web/modules/contrib/eca/modules/modeller_bpmn/src/ModellerBpmnBase.php(594): Drupal\eca_modeller_bpmn\ModellerBpmnBase->prepareConfigFields(Array)
#3 /opt/drupal/web/modules/contrib/eca/modules/modeller_bpmn/src/ModellerBpmnBase.php(549): Drupal\eca_modeller_bpmn\ModellerBpmnBase->properties(Object(Drupal\augmentor\Plugin\Action\AugmentorAction), 'action', 'bpmn:Task', Array)
#4 /opt/drupal/web/modules/contrib/bpmn_io/src/Plugin/ECA/Modeller/BpmnIo.php(76): Drupal\eca_modeller_bpmn\ModellerBpmnBase->getTemplates()
#5 /opt/drupal/web/modules/contrib/eca/modules/ui/src/Controller/EcaController.php(206): Drupal\bpmn_io\Plugin\ECA\Modeller\BpmnIo->edit()
#6 [internal function]: Drupal\eca_ui\Controller\EcaController->edit('process_ve9lv20')
#7 /opt/drupal/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array(Array, Array)
#8 /opt/drupal/web/core/lib/Drupal/Core/Render/Renderer.php(592): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#9 /opt/drupal/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(121): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#10 /opt/drupal/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array)
#11 /opt/drupal/vendor/symfony/http-kernel/HttpKernel.php(181): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#12 /opt/drupal/vendor/symfony/http-kernel/HttpKernel.php(76): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#13 /opt/drupal/web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#14 /opt/drupal/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#15 /opt/drupal/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#16 /opt/drupal/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#17 /opt/drupal/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#18 /opt/drupal/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#19 /opt/drupal/web/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(51): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#20 /opt/drupal/web/core/lib/Drupal/Core/DrupalKernel.php(704): Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#21 /opt/drupal/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#22 {main}