Got error 28 from storage engine SELECT O.ID AS ObjID, O.UID AS ObjUID, O.OwnerID AS ObjOwnerID, O.RightID as ObjRightID ,RTC.Description AS rtcDescription, RTC.PreviewImageFN AS rtcPreviewImageFN, RTC.Duration AS rtcDuration, RTC.GiveCertificate AS rtcGiveCertificate, RTC.Name AS rtcName, RTC.RootThemeID AS rtcRootThemeID, RTC.IsPublic AS rtcIsPublic, RTC.ShowStructureInDesc AS rtcShowStructureInDesc, RTC.AllowGroupWork AS ctoAllowGroupWork, RTC.GrpWSeVisibilityTypeID AS ctoGrpWSeVisibilityTypeID, RTC.GroupWorkPlanRootThemeID AS ctoGroupWorkPlanRootThemeID FROM objects O INNER JOIN rtcourses RTC ON RTC.ID=O.ID WHERE (O.available = 1) AND RTC.IsPublic=1 ORDER BY O.ID