"This app can't be opened" [Halo 5: Forge PC]

Games Halo 5: Guardians
1

Processor
AMD FX-8320E Eight-Core Processor

Video Card
AMD Radeon R7 370 Series

Video Card #2
AMD Radeon ™ R7 370 Series

RAM
12 GB

Operating System
Microsoft Windows 10 (build 10586), 64-bit

2

I have the exact same issue