IJCAD version upgrade prevents Gcad.Application objects from being retrieved

The program that works with IJCAD in VBA is
by updating IJCAD (2018→2019) Runtime Error 91 Object Variable with Block Variable is now displayed.

The VBA reference setting has been modified to 2019 in Gcad.
The CAD you are working with will still fail when it is started.

DimgetTimesec As Double
Dim GcadApp As GcadApplication
Set GcadApp=GetObject(, "Gcad.Application")　　← Object not retrieved in this line
Set GcadDoc= GcadApp.ActiveDocument

Is it because of the version of IJCAD that the object is no longer available, or is the code strange?
I'm a beginner at VBA, so I don't know if the above information is enough for me to make a decision, but I appreciate your cooperation.