Error when publishing combined files

Hi, I have 2 separate storyline files both created in Storyline 360. Both files is working fine when published and or preview but when combined, like import file#1 to file #2  Storyline will crash and show this error.

Can someone help me how to fix this error or tell me what this error is? I have submitted the error report by clicking send on the popup but the problem still persist.

<?xml version="1.0" encoding="utf-16"?>
<ErrorReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
 <UserId><LINE REMOVED FOR SECURITY PURPOSES ></UserId>
 <HardwareId><LINE REMOVED FOR SECURITY PURPOSES ></HardwareId>
 <Message>StartIndex cannot be less than zero.
Parameter name: startIndex</Message>
 <StackTrace> at StringBuilder System.Text.StringBuilder.Remove(int startIndex, int length)
 at string Articulate.Collections.CollectionItem.GetRelativeKey(ICollectionItem oTarget, object context)
 at List&lt;bwAction&gt; Articulate.Design.Shape.GetSaveStateActions(bwObject obj, ITriggerBase trigger, object context, object variablesStorageContext)
 at void Articulate.Design.Triggers.TriggerPublish.SaveShapeState(IActionList events, ITriggerBase trigger, bwObject _bwObject, object context, object variablesStorageContext)
 at void Articulate.Design.Triggers.TriggerPublish.PublishActions(IActionList actions, IPlayerService service, bwObject _bwObject, ITriggerBase trigger, object context, string targetWindow, bool reverse, bool forceActionGroup, string actionGroupName, object variablesStorageContext)
 at void Articulate.Design.Triggers.TriggerPublish.PublishOnMouseHoverTrigger(IPlayerService service, List&lt;bwEvent&gt; eventsList, bwObject _bwObject, ITriggerBase trigger, object context, string targetWindow, object variablesStorageContext)
 at void Articulate.Design.Triggers.TriggerPublish.PublishTriggers(IPlayerService service, List&lt;bwEvent&gt; eventslist, bwObject _bwObject, IReadOnlyList&lt;ITriggerBase&gt; list, object context, object variablesStorageContext)
 at void Articulate.Design.Triggers.TriggerCollection.Publish(IPlayerService service, List&lt;bwEvent&gt; eventslist, bwObject obj, object context, List&lt;ITriggerBase&gt; customtriggers, object variablesStorageContext)
 at void Articulate.Design.Shape.PublishTriggers(IPlayerService service, bwStageObject stageObj, bwSlideBase slide)
 at bwStageObject Articulate.Design.Shape.GetStageObject(IPlayerService service, bwSlideBase slide)
 at bwStageObject Articulate.Design.Shape.Articulate.Player.IPlayerShape.GetStageObject(IPlayerService service, bwSlideBase slide)
 at void Articulate.Player.PlayerContentPublisher.a(IEnumerable&lt;IPlayerShape&gt; A_0, bwSlideBase A_1)
 at void Articulate.Player.PlayerContentPublisher.a(IPlayerSlide A_0, bwSlide A_1)
 at bwSlide Articulate.Player.PlayerContentPublisher.CreateSlideObject(IPlayerSlide slide, bwISlideContainer sceneobj)
 at void Articulate.Player.PlayerContentPublisher.CreateBridgewaterSlide(PlayerWriterSettings settings, IPlayerSlide slide, bwISlideContainer sceneobj)
 at bool Articulate.Player.PlayerContentPublisher.CreateContentScenes(PlayerWriterSettings settings, IPlayerContentProvider contentProvider)
 at bwContent Articulate.Player.PlayerWriter.WriteContent(IPlayerContentProvider contentProvider)
 at bool Articulate.Player.PlayerWriter.Write(IPlayerContentProvider contentProvider)
 at void or.n()
 at void Articulate.Design.Publish.TargetContext+PublishBackgroundWorker.OnDoWork(DoWorkEventArgs e)
 at void Articulate.ComponentModel.STABackgroundWorker.a(object A_0)</StackTrace>
</ErrorReport>