To reproduce:
1. Open attached project.
2. Play "test" scene.
3. Wait 1-20 seconds for a crash. Also animation has no visual effect, because Enable/Disable states are not saved to the keyframes, but keyframes are created.

Reproduced with: 5.5.0b3, 5.5.0f3
No reproduction: 5.4.3f1, 5.6.0a1

Repro with win7. Previously crashed every time. For some reason now it happens not every time, but most of the times.
No repro with win10.

Fixed in 5.6
//LineRenderer's Enabled/Disabled states are saved to the keyframes and it does not crash.

Might be that this case and 854386 are related. Stack trace is almost identical, and both issues are about animating some property of LineRenderer.