hello all,im new to this forum but have been using cad since release 12. but have only now been getting this error message ARX_ERROR: eNotThatKindOfClassbut only in a couple of files. anyone came across this before? only way i have found to get rid of it is to create a new files and then copy and paste everything into the new file. but when you have 15 paper space tabs it takes forever and then having to reset all the viewports.i use AutoCAD2006 just now but also have AutoCAD2009 installed. but need to upgrade memory to run it properly, while i get funds for a new machine.any help is appreciated.Ian

It becomes when there is new objects in the drawing (eg. from newer version of cad). Install Object Enabler (you'll find it here in Downloads).More information in tip #4922 or eg. here... (doesn't matter that it is for MAP, I thing, it's similar)Kackac2008-12-01 14:42:36

[QUOTE=iwaddell]hello all,im new to this forum but have been using cad since release 12. but have only now been getting this error message ARX_ERROR: eNotThatKindOfClassbut only in a couple of files. anyone came across this before? only way i have found to get rid of it is to create a new files and then copy and paste everything into the new file. but when you have 15 paper space tabs it takes forever and then having to reset all the viewports.i use AutoCAD2006 just now but also have AutoCAD2009 installed. but need to upgrade memory to run it properly, while i get funds for a new machine.any help is appreciated.Ian
[/QUOTE]Check this URL:http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=7047371&linkID=9240618

thanks guys,much appreciated with the information about the error message. problem solved.cheersian