Roblox Studio doesn’t really have a legitimate “bypass” for converting meshes. The usual answer is that .mesh files aren’t supported for asset uploading, so you need to use a supported format like .obj or .fbx, or work with mesh parts through Roblox’s built-in mesh workflow.

What the community says

A Roblox DevForum thread specifically says you can’t upload .mesh files as assets in Studio, even though they can exist as local files. Another DevForum discussion notes that MeshPart mesh IDs can’t be changed freely in scripts, so there isn’t a script trick that fully bypasses the limitation.

Practical options

  • Convert the mesh in Blender or another 3D tool, then import it as .obj or .fbx.
  • If you already have a SpecialMesh, you can create a MeshPart through Roblox’s supported creation flow rather than trying to overwrite restricted properties.
  • If the issue is import errors, check for flipped faces, too many triangles, or exporting from the wrong mode, since those are common causes of broken imports.

Important limit

If your goal is to upload or load a .mesh file directly as a Roblox asset, the answer appears to be no based on the sources above.

Safe workaround

A clean workflow is:

  1. Open the mesh in Blender.
  2. Fix normals, triangle count, and scale.
  3. Export as .fbx or .obj.
  4. Import into Roblox Studio.

That is the most reliable path for getting the result you want without fighting the format restrictions.

TL;DR

There’s no real bypass for Roblox Studio’s mesh conversion restrictions; use a supported import format instead.