Enabling Crypto breaks packaging

I can build a shipping package for windows on an existing project.

When I click Generating New Encryption Key, it still builds, but then if I enable any Encrypt otions, it fails to build.

-edit Also, Clearing the encryption key and enabling any Encrypt options still builds.

Exact same thing in brand new project.

The errors are;
LogTemp: IPP ERROR: Could not find provision directory ‘C:\Users\Chris\AppData\Local/Apple Computer/MobileDevice/Provisioning Profiles/’.

UATHelper: Packaging (Windows (64-bit)): ERROR: Windows SDK v8.1 must be installed in order to build this target.

PackagingResults: Error: Windows SDK v8.1 must be installed in order to build this target.

UATHelper: Packaging (Windows (64-bit)): Took 6.9088726s to run UnrealBuildTool.exe, ExitCode=5

The UELinkerFixups.cpp file is autogenerated, and is set with a key length of 32 when generating the EncryptionKeyCallback

In our project, the old key was 64 chars. So regenerating the key generates a 32 char key and the file compiles and then links.

Go to Project Settings->Crypto
Check the length of the Encryption Key – if it’s longer than 32 chars, regenerate it.