Unknown Error: Move Along Path

Klaus

I get this error when trying to move along path. To solve the problem i have to delete my module ang create a new one then it works.

RobotStudio .NET exception dump
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Base exception:
'' is not a valid RAPID symbol name
   at ABB.Internal.RobotStudio.LgRapid.LgRAPIDTask.CheckRAPIDName( String name)
   at ABB.Internal.RobotStudio.LgRapid.LgDeclaration.Rename(String value)
   at ABB.Robotics.RobotStudio.Stations.RsDataDeclaration.set_Name (String value)
   at ABB.Internal.RobotStudio.API.HlpMotionFunctions.CreateUnique Declaration(UInt32 clientID, String systemID, RsTask task, RsInstructionArgument instructionArg, String moduleName, Hashtable* usedDeclarations, PostMotionCleanup* postCleanupObject)
   at ABB.Internal.RobotStudio.API.HlpMotionFunctions.InitializeIn structionDeclarations(UInt32 clientID, String systemID, RsTask task, RsMoveInstruction moveInstruction, String moduleName, Hashtable* usedDeclarations, PostMotionCleanup* postCleanupObject, Boolean* ignore)
   at ABB.Internal.RobotStudio.API.HlpMotionFunctions.MoveAlongPat h(RsPathProcedure sourcePathProcedure, ArrayList logMessageList)
   at ABB.Robotics.RobotStudio.Stations.RsPathProcedure.MoveAlong( ArrayList logMessageList)
   at ABBInternal.Controller.MoveMechanismCommands.MoveAlongPath_E xecuteCommand(Object sender, ExecuteCommandEventArgs e)
   at ABB.Robotics.RobotStudio.Environment.CommandBarButton.RaiseE xecuteCommand()

What can i do to solve this problem