Steps to reproduce:
1. Open attached project
2. Build on any platform

Expected behaviour: Project builds with no errors or crashes
Actual behaviour: Editor crashes after a few seconds

Reproduced on: 5.5.0p1, 5.6.0b1
Cannot check on 5.4 as it is not forwards compatible.

Won't Fix:
The problem is that the version of Mono.Cecil.dll that is being used in the project is incompatible with that used by Unity internally.

This can be fixed as follows:

On Windows, copy over the Mono.Cecil.dll from <unity_install_folder>\Editor\Data\MonoBleedingEdge\lib\mono\gac\Mono.Cecil\0.9.5.0__0738eb9f132ed756 (where that last folder name will probably vary by Unity version), to Assets\Mono\Cecil\Editor\Libs in the project folder.

On Mac, copy over the Mono.Cecil.dll from <unity.app : Show Package Contents>/Contents/MonoBleedingEdge/lib/mono/gac/Mono.Cecil/0.9.5.0__0738eb9f132ed756 (where that last folder name will probably vary by Unity version) to Assets\Mono\Cecil\Editor\Libs in the project folder.