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Fixed in Unity 2018.2



Found in


Issue ID




Editor crashes when loading a mesh asset with 'Mesh Compression' from an assetbundle

Asset Bundles



Priority: 2Necessary for shipping a final release


Severity: 1Crash, freeze, data loss, work stops

The crash happens if there's both an asset with 'Mesh Compression' enabled, and any other asset

Steps to reproduce:
1. Download and open the project
2. Click `Crash Repro->Build Bundles`
3. Click `Crash Repro->Load Assets` or `Crash Repro->Load All Assets`

Expected result: assets are loaded normally
Actual result: editor crashes

Reproduced on 2017.3.0a5, 2017.3.0p1, 2018.1.0b3
Not reproduced on 2017.2.1p1, 2017.3.0a1, 2017.3.0a4
Regression introduced in 2017.3.0a5

Verified FIXED 2018.1.0b5, 2018.2.0a3

Comments (3)

  1. D675478fd4aab2e632d02deecacb7de4?d=mm


    Nov 01, 2018 19:09

    We just ran into this same issue in 2018.3.0b8. After exhausting a bunch of other theories, I tried checking for this "fixed" bug and it resolved the issue. The game (or editor) would crash whenever we loaded a mesh from an asset bundle that had medium mesh compression enabled. We were also getting loads of assertion failures in the logs (Assertion failed on expression: 'meshVD.GetDataPtr() == NULL'). Disabling mesh compression, while not ideal, got rid of the assertions and the crash.

  2. Df4f9c27aa65f91ab13b610f5768cb76?d=mm


    Jan 24, 2018 15:54

    We have also run into this issue. In the editor we crash with a [Position out of bounds!] error. But when we run the code on an iOS device we still get the same error message/stack trace but we don't crash. Instead, meshes simply don't render on the device. We did some digging around and the meshes are empty (no verts). Crossing our fingers for a timely fix as we are trying to move our project to 2017.3.

    Reproduced on 2017.3.0f3.

  3. 7b05da8ca0232baf66a4a30dc0dd14b3?d=mm


    Jan 17, 2018 10:53

    Top prio and completely breaking 2017.3+for us.

    Every (Steam) PC game should use asset bundles and mesh compression, so this must affect all PC games?

    Please double check how this has passed unit testing since this is really basic.

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