Every Operation is being validated every time the Accept button is selected.
Also, the Macro is constantly being evaluated. Evaluation occurs every time the Accept button is selected and when Operations are moved in the Macro sequence.
After validation the process of Evaluation begins. When the Evaluation process concludes successfully the Macro Builder dialog reappears with the evaluated Macro.
With all the validation checks, there can not be checks on Lisp code ( if used ). You could write Lisp code that does not evaluate correctly and will stop the Lisp Evaluator.
If a Macro fails during evaluation the Macro Builder is stopped and the process is returned to AutoCAD. You will be stopped at the AutoCAD command line and the Macro Builder evaluation process is halted.
If and when this occurs you need to look at the text window in AutoCAD and see if you can get any information from the Lisp error. This information may help you debug the Macro.
Evaluation Error: What do I do?
•1) Do not exit AutoCAD or your Macro will be lost!
•2) Type MAC again at the AutoCAD command line immediately.
•3) The Macro Evaluation error box will appear and instruct you to correct the last edit.
•4) The Macro Builder dialog will reappear. All Save and SaveAs options will be disabled.
•5) Either, Reset to undo the last edit or correct the edit and Accept. The Macro will be evaluated again. If successful, Save it.
You should consider saving your Macro frequently. That way, if an error occurs and you can not figure it out, you have the last Macro definition that evaluates properly.