Editor crashes when you skip transcoding twice in a video.

Steps to reproduce:
1) Open the attached project
2) File > Build Settings
3)Switch the architecture (x86<>x64) or Switch platform
4) Select skip all transcoding
5) Repeat step 4
6) Observe the crash

Alternatively,

1) Create new project
2) Import any two sample videos. Apply transcode
3) File > Build Settings
4) Switch the architecture (x86<>x64) or Switch platform
5) Select skip all transcoding.
6) Repeat step 5
7) Observe the crash

Reproducible on : 2017.3.f3, 2017.3.f2, 2017.3.f1, 2017.3.b11, 2017.3.b5, 2017.3.a1

Works fine on : 2018.1.0b1, 2018.1.0a1, 2017.2.f3, 2017.1.f3

Regression on : 2017.3.0a1

Environment: Only on Windows