Why "copy and paste" into AutoCAD LT? Why not just open the exported dxf file in AutoCAD LT? AutoCAD 2022 doesn't allow me to paste from MoI either.

I do actually open the DXF file in AutoCAD. It's when I do a copy for eventual pasting from the DXF the DXF tells me the Copy to File has failed.

Even if I save it as a DWG file I still cannot Copy to File.

Oh, I got you. I'm seeing that as well now that I try it that way. I saved it to a dwg, closed the file, re-opened the dwg file and was able to copy and paste it.

Which version of MoI3D are you using cad-guy?

V4 and V5 beta. I tried it with both.

Just tried again with V4, just to be sure. Imported a PDF from a CAD file. Exported a dxf file. Opened the dxf in AutoCAD, saved the DWG. Opened the dwg again in AutoCAD 2021 and I can now, copy and paste.

This will be fixed in the next v5 beta. It had to do with handle values in the DIMSTYLE table getting modified.

Part of the dimensions support that was new in v4 was reading and writing dimension entities and also
DIMSTYLEs to DXF files. The fix is to make sure not to modify the DIMSTYLEs that are already in place
in the DXF template file before MoI adds any new ones.

When the handle values were updated, it caused some other piece to have an invalid reference to a dimstyle
which then triggers the copy to clipboard problem later on.

Only AutoCAD was affected and not any other programs because only AutoCAD reads in every single little
complex detail ("reactors", viewport setup blocks, dimension arrowhead blocks, etc...) out of a DXF file.

- Michael