I think you have to set the type subcategory. Try this (not tested)API_ToolBoxItem elemType = {}; elemType.type.typeID = API_ObjectID; elemType.type.variationID = APIVarId_Object; ACAPI_Element_CatchNewElement(&elemType, ElementEventHandler);

Thanks a lot, that helped me.I made it myself up to the 4th point but didn't know I have to use VectorImage. And actually I used ACAPI_Attribute_GetDefExt() not the memo. Attribute_Test example has the correct code. Thanks again!

Archicad updates are done manually - you have to check if there is new version of the app and/or the library (go to Help --> Check for Updates...). On the other hand Visual Studio does this automatically - you see a notification like thisIn both case...