sure generally meshing thin/hollow structures is not impossible, but especially in frame designs like yours there often occur problems at the junctions when multiple tubes are merged. This often leads to geometry artifacts if the merged solids are not modeled very accurately. In your case I can also spot some areas where the fusion of solids seems incorrect:
Maybe you can go back to your CAD tool and search for small/sliver faces that could be removed or self-intersections and have a close look at the junctions of they are merged correctly.
After this has been cleaned up, there should not be any reason why the model shouldn’t mesh - the thin structure of it will just create a very large mesh.