Before you can start the Debugger in attachable mode, you have to ready the process for debugging. The process can be any ABL (GUI or character mode) client, WebSpeed agent, or AppServer process, but not a WebClient™ process. You can make the process ready for debugging by:

While a process is debug-ready, it might run slower than normal. Therefore, you should turn on this capability only when you intend to use the Debugger in attachable mode.