I get the following error if in the editor i try to make a link to a file and want to track its download. What can be the issue of this , never saw it before

Message: System.Exception: Unhandled Error: ---> System.NullReferenceException:

Object reference not set to an instance of an object. at DotNetNuke.Services.FileSystem.FileController.ConvertFilePathToFileId(String filePath, Int32 portalID) at DotNetNuke.Providers.RadEditorProvider.LinkClickUrlHandler.GetLinkUrl(DialogParams& params, String link) at DotNetNuke.Providers.RadEditorProvider.LinkClickUrlHandler.GetLinkClickURL(DialogParams& params, String& link) at DotNetNuke.Providers.RadEditorProvider.LinkClickUrlHandler.HandleRequest() at DotNetNuke.Framework.BaseHttpHandler.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) --- End of inner exception stack trace ---