Hi, when the command opndcl is missing, the opendcl is not registered properly. It can happen if the 3rd party app or OpenDCL were installed before AutoCAD or AutoCAD was reinstalled. I recommend to reinstall your 3rd party app or OpenDCL again and make sure that OpenDCL can be load on demand (maybe there are some special security settings in your company to prevent 3rd party apps being loaded).
Regards, Fred