check that ARX application is active in the AutoCAD support path or not.
1) Make sure the ARX file reported in the error is in the AutoCAD support path. (Search on Support File Search Path in the AutoCAD 2000 Users Guide online help for details how to do this.)
2) Type appload on the command line to display the 'Load/Unload Applications' dialog box.
3) Browse to the location of the ARX file reported in the error message.
Select the file and choose the Load button. A text window in the bottom left of the dialog box will indicate if the file was loaded successfully.
4) Choose Close when finished.
If the ARX application is in the AutoCAD support path but it cannot be loaded, that means there are insufficient system resources to load it into memory.
Cheers !!!
dnyanesh kamthe