Its’ latest sighting is yesterday when an Electrical Autocad Technician is trying to convert an MEP2 2008 drawing to plain Autocad. Engineers from site requested him an Autocad version of one of the Electrical drawings of the project which we created in Autocad MEP (Previously ABS 2007.1) for their reference. For them to open the drawings properly the cad operator should convert it first to plain cad version otherwise the objects in the requested drawing will just appear like a series of rectangles and N/A. This problem has been mentioned in this post Autocad MEP Problems / Bugs.

So back to the simple file conversion task, normally to convert the MEP 2008 drawings to a plain Autocad version. Here are the common ways to make it happen.

• by envoking the command: “etransmit”
• by exporting to autocad, command: “_AecExportToAutoCAD2004“
• by converting to dxf via command: “dxfout”

He chose the second and to his surprise the friendly Unhandled Access Fatal Error showed. So this is the case where I have to enter the CADD scene to act like Mr. Cadd Inspector. I have to find a way to export the problematic MEP 2008 file to Autocad and the same time explore the problem.

The MEP 2008 Problem: Fatal Error occured while converting the AutocadMEP 2008 drawings to normal Autocad (any versions)

Actions Taken that didn’t work out:

• Export to Autocad version 2007
• Export to Autocad version 2004
• Copied all the objects of the affecetd drawings and paste it in new drawing, then run the export command
• Removed all the xref files, purge, building sytem purge (BldSysPurge) then export
• Unfroze, unthawed, unlocked and reconcilled all the layers

All of the above actions didn’t give positive outcome. All of them just resulted to the stubborn “fatal error” box. Of course, recreating the whole drawing is not an option

the MEP 2008 drawing loaded with electrical device, custom wire styles and tags

The Work Around

Actually, to workaround this problem, all we have to do is run a series simple and common commands. Here are the four steps to deal with it.

1. Select all the MEP objects in the drawing
2. Explode (Only once so as not to disarray the device and annotation symbols)
3. Bind the xref files
4. Saveas to required Autocad version

Exploding an MEP object will convert it to autocad block. Exploding it again will make the block separate lines or arcs.

Another observation for this workaround is that after exploding, the colors will be changed according the original color setting assigned on block of the device. It will not retain the color as set by the MEP 2008 layer keys.

Screenshot before exploding . Note the device and drawing object colors.

Screenshot after exploding . Note the device and drawing object colors.

I observe the changing color as follows:

• If the drawing block color is set to “bylayer”, after exploding the color become the default color which is white
• If the drawing block color is set to “green” (or any other color), after exploding the color will become “green” (or any other color).

This is not the perfect solution but atleast I can can now the converted Autocad drawings which is needed urgently by our people on site. As to why the error occurs, I still don’t know. Errors such as this is really unpredictable in this software and requires indepth knowledge of the software.  Afterall Autodesk has a well experienced team that can deal with it extensively.  Should they need error reference to start debugging where the error originates I’m sure they have plenty of error files to start,  I’ve sent them bunch these using Autocad MEP 2008 auto-generated error report.

I wish this problem will not be around on the Autocad MEP 2009.

Fatal Error: Unhandled Access while exporting to Autocad MEP 2008 to Autocad is a post from: Free Cad Software