Hololens sharing tutorial with PUN2

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Hello; I've come to Photon after trying and failing to get the Mixed Reality Academy sharing tutorials and UNET tutorials to work properly with Hololens and Unity. I've scoured the internet for snippets of information and tried to piece together what I can. The description below sounds like a simple game to make, and the way I believe Photon allows a multiplayer to be built (please correct me if I'm wrong), but when it comes to deploying to Hololens, I always run into errors, so here I am to ask for your help!

1) I want to make a Hololens-based multiplayer game where one person is the server / host, and others can join the game
2) The host can move objects / prefabs / 3D models in different scenes
3) The others should be able to see what the host is doing, but they don't have to interact with them or the objects (if they can without much extra work, then that's a bonus)
4) The others can leave the game when they like
5) When the host ends the game, everyone else leaves the game

I am building with:
- Holotoolkit 2017.4.3.0 because if I build with Mixed Reality Toolkit I get other errors with other parts of my game and its SDKS
- Unity 2017.424f1 because this has been the most stable for the above reason too
- PUN2

I have followed the PUN Basics tutorial and successfully got it to work on PCs and the Unity editor between 3 computers.

I get errors such as:
Plugin 'Photon3Unity3D.dll' is used from several locations:
 Assets/Photon/PhotonLibs/Photon3Unity3D.dll would be copied to <PluginPath>/Photon3Unity3D.dll
 Assets/Photon/Photon3Unity3D.dll would be copied to <PluginPath>/Photon3Unity3D.dll
Please fix plugin settings and try again.
Plugins colliding with each other.
Then I try deleting some of the .dll files (as suggested by another forum post, and then I can build to PC, but when building to Hololens, I get these errors, and yet it also tells me it's built with a result of "Succeeded":
Reference rewriter: Error: type `System.Security.Cryptography.HMACSHA256` doesn't exist in target framework. It is referenced from Photon3Unity3D.dll at System.Boolean ExitGames.Client.Photon.EncryptorManaged.Decryptor::CheckHMAC(System.Byte[],System.Int32).
UnityEngine.Debug:LogError(Object)
PostProcessWinRT:RunReferenceRewriter() (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/PostProcessWinRT.cs:989)
PostProcessWinRT:Process() (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/PostProcessWinRT.cs:211)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)
And others such as System.Void System.Threading, Socketflags, etc.

I then take my "successful" Hololens build into Visual Studio in order to deploy to the Hololens, but then get these errors:
Severity	Code	Description	Project	File	Line	Suppression State
Warning	CS0618	'ApplicationView.SuppressSystemOverlays.set' is obsolete: 'Use the TryEnterFullScreen method and IsFullScreenMode property instead of SuppressSystemOverlays. For more info, see MSDN.'	Photon_test	D:\Unity Projects\Photon_test\Builds HL\Photon_test\App.cs	56	Active
Severity	Code	Description	Project	File	Line	Suppression State
Error		The command ""D:\Unity Projects\Photon_test\Builds HL\Unity\Tools\AssemblyConverter.exe" -platform=uap -lock="D:\Unity Projects\Photon_test\Builds HL\Photon_test\project.lock.json" -bits=32 -configuration=Release -removeDebuggableAttribute=False -uwpsdk=10.0.17763.0 -path="." -path="C:\Program Files\Unity\Hub\Editor\2017.4.24f1\Editor\Data\PlaybackEngines\MetroSupport\Players\UAP\dotnet\x86\Release" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.TerrainModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.StyleSheetsModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.TerrainPhysicsModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.TilemapModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.TextRenderingModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.SpriteShapeModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.PhysicsModule.dll" "D:\Unity Projects\Photon_test\Builds HL\Photon_test\UnityEngine.Physics2DModule.dll" "D:\Unity Projects\Photon_test\Builds
(I can't add all the code above because I've gone over my character limit!)

Any suggestions or help would be wonderful; I have been stuck on networking and sharing for a long time, but it seems it's not an easy task either!

Thanks in advance!

Sarah