I am trying to create a workflow (According to the "Approval - Sharepoint 2010" template) and to activate "Enable Content Approval" in it, this works fine, but it doesn`t do anything.
Some research resulted in the site feature "Workflows can use app permissions" to be nessessary to use this feature.
So I go to the site that contains the library, go to "Site settings", "Manage site features", look for the feature and click the Activate-button.
Doing that results in this error message
Using the Correlation ID I was able to find this stack trace, which seems to maybe explain why it does not work:
Unexpected Microsoft.SharePoint.WorkflowServices.NotConnectedException: Exception of type 'Microsoft.SharePoint.WorkflowServices.NotConnectedException' was thrown. at Microsoft.SharePoint.WorkflowServices.SPAppOnlyPolicyManagerFeatureReceiver.ConfigureAppOnlyPolicy(SPFeatureReceiverProperties properties, Boolean isAppOnly) at Microsoft.SharePoint.SPFeature.DoActivationCallout(Boolean fActivate, Boolean fForce) at Microsoft.SharePoint.SPFeature.Activate(SPSite siteParent, SPWeb webParent, SPFeaturePropertyCollection props, SPFeatureActivateFlags activateFlags, Boolean fForce) at Microsoft.SharePoint.SPFeatureCollection.AddInternal(SPFeatureDefinition featdef, Version version, SPFeaturePropertyCollection properties, SPFeatureActivateFlags activateFlags, Boolean force, Boolean fMarkOnly) at Microsoft.SharePoint.SPFeatureCollection.AddInternalWithName(Guid featureId, Int32 compatibilityLevel, String featureName, Version version, SPFeaturePropertyCollection properties, SPFeatureActivateFlags activateFlags, Boolean force, Boolean fMarkOnly, Boolean fIgnoreMissing, SPFeatureDefinitionScope featdefScope) at Microsoft.SharePoint.WebControls.FeatureActivator.ActivateFeature(Guid featid, Int32 compatibilityLevel, SPFeatureDefinitionScope featdefScope) at Microsoft.SharePoint.WebControls.FeatureActivatorItem.ToggleFeatureActivation() at Microsoft.SharePoint.WebControls.FeatureActivatorItem.BtnActivateFeature_Click(Object objSender, EventArgs evtargs) at System.Web.UI.WebControls.Button.OnClick(EventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
Sadly I do not know what this means, and I couldn`t find anything on Google.
I hope someone can explain what this means, or maybe even tell me, how to solve this problem.