Connection problems with external programs when communicating with AutoCAD

[TSKZ]

Hello,

Since the change from AutoCAD (Mechanical) 2018 to 2022 we have several problems with the communication of our external AutoCAD programs to the AutoCAD client.

The messages are always:
Call was rejected by callee. (Exception from HRESULT: 0x80010001 (RPC_E_CALL_REJECTED))”

The programs are based on C# with reference to "C:\Program Files\Common Files\Autodesk Shared\acax24enu.tlb."

A conversion to AutoCAD internal running programs (dll) is not possible at the moment.

The hints in "Handling COM calls rejected by AutoCAD from an external .NET application" do not help or better not clear enough for me.

What else can I do or what am I doing wrong?

Greetings tom

[norman.yuan]

It is very difficult to say/suggest anything meaningful without knowing what "external AutoCAD program" and "AutoCAD client" are, and how they are supposed to work.

Just a shot in the dark: whatever the "external AutoCAD program" and/or "AutoCAD client" are, it is possible to communicate with running AutoCAD session through AutoCAD COM API, and the "program"/"client" was early bound to AutoCAD COM API (Acad2018).  Since you mentioned the reference to "C:\.....\acax24enu.tlb"), does that mean that the program has been recompiled with the COM API type library of Acad2022?

[TSKZ]

"External AutoCAD program" means my written C# program with AutoCAD COM API. And "AutoCAD client" means AutoCAD itself.

Yes, the program was recompiled with the COM API type library of Acad2022.

I found out that when the connection problem happens and I press the ESC key on AutoCAD side (inside the drawing) and go back to my program and run the command again then it often works.

Strange.