Most modern PowerMill post processors are not simple text files; they are executable logic engines (often written in languages like C# or utilizing specific post-processor kernels like the Autodesk Manufacturing Post Processor Utility). When you click "Write," PowerMill feeds the CLDATA (Cutter Location Data) into the post-processor. If that stream of data is interrupted, or if the post-processor fails to launch or crashes mid-process, PowerMill reports that the "connection" to the post-processor was broken.

After years of field experience and forum deep-dives, almost all "broken connection" errors fall into one of these eight categories.

: The COM (Component Object Model) registration for the post-processor is broken or missing.

To understand the error, we need a quick lesson in how PowerMill talks to its Post Processor.

In essence: The translator didn’t get the full book—only the first few chapters—and crashed.

The (PM-Post or PMOPTZ) acts as the translator. It reads the APT stream line-by-line and converts it into machine-specific G-code.

If the error persists after these checks, the post processor file itself is likely corrupted — recreate it using (formerly PMPost).