THe problem is that at one point, someone inserted a 3D Solid, surface or something into this drawing.
This marks the drawing as "I need the solid modeler to display this drawing", so when AutoCAD open the drawing, it tries to load the modeler dll's.
Even if you delete those solid/surface objects, the drawing is still marked as "I need the modeler".
So.. There's something wrong with your installation here, with the modeler. The other users here DON'T get any error message, as the modeler is loaded as needed. This is what it look like when I open your drawing:

No error message, just an informational message that the modeles dlls are loaded.
The solution... First, fix you AutoCAD Installation.
And then, use the WBLOCK (as mentioned earlier in this thread) to save the entities in your drawing to a new drawing.
*Hint: Turn on all attributes by setting ATTDISP to ON first. Remember to set it back to "Normal" afterwards.
Trond Hasse LieEPLAN Expert and ex-AutoCAD Electrical user.
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