Unity Hololens 1st Generation Development Issues
Software and plug-in version
Use U3D version untiy2019.4.11f1, Mixed Reality Toolkit plug-in version V2.6.1 URL https://github.com/microsoft/MixedRealityToolkit-Unity/releases/tag/v2.6.1.
Encounter problems
1. Build Settings reports a warning 
2. Releases an error
'FALSE != acquireNewContextResult'
WSATestCertificate.pfx does not exist
Failed to open Assets\WSATestCertificate.pfx
3. Deployment error
Problem 1 Warning Solution
Open the VS version you are currently using, Tools->Get Tools and Functions->Universal Windows Platform Development->C++ Universal Windows Platform Tools Installation, successfully solve the problem
Issue 2 Publish the error solution
Solution 1: Update win10sdk tools -> get tools and functions -> general windows platform development -> choose a version of win10SDK to install, there is a problem with the test release. Unresolved
After installing all the SDKs, an error still occurs! ! !
Solution 2: Get the file from other sample projects and use it. It is feasible to pack it without any problem.
Problem 3 deployment error solution
Solution to the first error report: The error was reported because the release was 64-bit, but hololens1 was 32-bit. The
second error report solution: First, the system of hololens itself was updated, and the old web page was replaced with For a new web page, modify the content of the Builds\WSAPlayer\Hololens\Package.appxmanifest file, and directly delete the section with splashscreen image = "Assets\Splashscreen.png", whether it is to update the system or delete the modified file has played a role, not to If you have the above problems, you can test both methods.
After testing, it is found that whether the file is modified or not has no effect! ! !