: If a custom application or script is trying to execute a command through the VL.CRX interface, errors within the application or script can cause this exception. This could be due to bugs in the code, incorrect usage of AutoCAD's API, or incompatibility with the version of AutoCAD being used.
Use or launch with:
(defun c:testnil () (princ "VL loaded") (princ) ) autocad exception in vl.crx arx command