For the export to Windows 8.1, you might have to setup the export rules for some assemblies (.dll files) in Unity 5.
Please try this setup:
\Plugins\WP8\Photon3Unity3D.dll
-> Check only WP8Player under platform (any CPU). Add a "Placeholder": \Plugins\Photon3Unity3D.dll. Leave "Don't process" off (as last resort, you could try to check that).
\Plugins\Photon3Unity3D.dll
-> Check all platforms except WP8, WSA and Blackberry.
\Plugins\Metro\Photon3Unity3D.dll
-> Check only platform WSAPlayer.
\Plugins\WebSocket\websocket-csharp.dll
-> Only platform is Editor.
Make sure to check "Internet Client" in the publishing settings for Windows RT/Phone.
These settings also apply to Photon Chat and can be used for the Photon Unity SDK as well.
If you have issues with this, please let us know here.
Please try this setup:
\Plugins\WP8\Photon3Unity3D.dll
-> Check only WP8Player under platform (any CPU). Add a "Placeholder": \Plugins\Photon3Unity3D.dll. Leave "Don't process" off (as last resort, you could try to check that).
\Plugins\Photon3Unity3D.dll
-> Check all platforms except WP8, WSA and Blackberry.
\Plugins\Metro\Photon3Unity3D.dll
-> Check only platform WSAPlayer.
\Plugins\WebSocket\websocket-csharp.dll
-> Only platform is Editor.
Make sure to check "Internet Client" in the publishing settings for Windows RT/Phone.
These settings also apply to Photon Chat and can be used for the Photon Unity SDK as well.
If you have issues with this, please let us know here.