Debugging

Every SolidWorks API developer has spent hours debugging a macro that produces no error, no exception, and completely wrong output. The SolidWorks COM API is old enough that many of its failure modes predate modern error handling conventions — methods that silently return Nothing, boolean flags that are ignored, and side effects that modify document state without warning. This is a catalogue of the seven most common ones. Each has a pattern, a root cause, and a fix. ...