Autodesk Platform Services (APS)AutoCAD Automation API execute customization by accoreconsole.exe, console version of AutoCAD, in behind. The accoreconsole.exe doesn't support AutoCAD ActiveX API. VLA* functions in AutoLisp invoke AutoCAD ActiveX API so the your Lisp causes error on APS. I recomend you porting your customization by AutoCAD .NET API as AutoCAD addin, which can loaded by accoreconsole.exe.