Hi all I am trying to set the properties for balloons in vba. I want to specify to use a custom block rather than the standard balloon. It's fine for creating new drawings - I have set it up in the templates but for existing drawings, I want to automatically set it up in the code. I get a Fatal Error: Unhandled Access Violation Exception when it gets to the code to update the block name. The code I am trying to use to is as follows: dim oSymMgr as McadSymbolBBMgr dim oStdMgr as McadStandardMgr dim oBomStd as McadBOMStandard set oSymMgr = ThisDrawing.Application.GetInterfaceObject("SymBBAuto.McadSymbolBBMgr") set oStdMgr = oSymMgr.StandardMgr set oBomStd = oStdMgr.currentStandard.BOMStandard oBomStd.BalloonStandard.customBlockName = "PB" Any help in resolving this problem would be greatly appreciated. Many thanks, Laura.