I'm currently working on a uSkinned Website running Umbraco 8. When uploading an image via the drop zone it doesn't work and displays an error. However, clicking on "Create" works just fine. Currently working on Umbraco 8.18.4.

Error message in the logs:

Unhandled controller exception occurred for request '"https://www.bolliger-holz.ch/umbraco/backoffice/UmbracoApi/Media/PostAddFile
System.NullReferenceException: Object reference not set to an instance of an object. at Umbraco.Web.Editors.MediaController.GetParentIdAsInt(String parentId, Boolean validatePermissions)
   at Umbraco.Web.Editors.MediaController.<PostAddFile>d__23.MoveNext()
--- End of stack trace from previous location where exception was thrown ---"''

Any help is appreciated.

Cheers Timon