There was an internal issue with the rendering process

I am using Xamarin on Visual Studio Enterprise 2017 RC on Windows 10. I linked up Xamarin to my Mac build server. When I try to preview the default app template with the Previewer, I get this error:

Logs attached. In particular, it looks like it's iOS that is screwing up.

system: Dec 25 05:11:35 ns ids_simd[6182]: (Error) IDSSimulatorSupport: <IDSSimSupportLocalServer.m __68-[IDSSimSupportLocalServer setNetworkSimulation:enabled:completion:]_block_invoke:544> message send of data {
        ControlCmd = SetNetSimulationEnabledCmd;
        Enabled = 0;
        ServiceName = "com.apple.private.alloy.sockpuppet.classd";
    } failed with error Error Domain=com.apple.idssimualtorsupport.errors Code=2 "(null)" UserInfo={NSUnderlyingError=0x7fec4ad19880 {Error Domain=NSMachErrorDomain Code=268435459 "(ipc/send) invalid destination port"}}
Dec 25 05:11:35 ns companionappd[6187]: (Error) WatchKit: <SPTransport.m __67-[SPTransport service:account:identifier:didSendWithSuccess:error:]_block_invoke:415> __67-[SPTransport service:account:identifier:didSendWithSuccess:error:]_block_invoke identifier (3BC7427D-2DDA-4FDD-821A-4EE4E1F6D8BF), serviceName ((null)), success: 0 error, domain: com.apple.identityservices.error, code: 23
Dec 25 05:11:35 ns companionappd[6187]: (Error) WatchKit: <SPCompanionAppServer.m __75-[SPCompanionAppServer sendProtobuf:sender:timeOut:allowInsecureTransport:]_block_invoke:894> sendProtobuf failed, error : Error Domain=com.apple.identityservices.error Code=23 "Timed out" UserInfo={NSLocalizedDescription=Timed out, NSUnderlyingError=0x7fada3c26e50 {Error Domain=com.apple.ids.idssenderrordomain Code=12 "(null)"}}
Dec 25 05:11:35 ns companionappd[6187]: (Error) WatchKit: <SPTransport.m __67-[SPTransport service:account:identifier:didSendWithSuccess:error:]_block_invoke:415> __67-[SPTransport service:account:identifier:didSendWithSuccess:error:]_block_invoke identifier (83FF6432-F944-4F84-945E-FBE6C35FD8EF), serviceName ((null)), success: 0 error, domain: com.apple.identityservices.error, code: 23
Dec 25 05:11:35 ns companionappd[6187]: (Error) WatchKit: <SPCompanionAppServer.m __75-[SPCompanionAppServer sendProtobuf:sender:timeOut:allowInsecureTransport:]_block_invoke:894> sendProtobuf failed, error : Error Domain=com.apple.identityservices.error Code=23 "Timed out" UserInfo={NSLocalizedDescription=Timed out, NSUnderlyingError=0x7fada3c260a0 {Error Domain=com.apple.ids.idssenderrordomain Code=12 "(null)"}}

system: Dec 25 05:11:42 ns sharingd[6193]: 05:11:42.580 : Failed to send SDURLSessionProxy startup message, error Error Domain=com.apple.identityservices.error Code=23 "Timed out" UserInfo={NSLocalizedDescription=Timed out, NSUnderlyingError=0x7ff483482a10 {Error Domain=com.apple.ids.idssenderrordomain Code=12 "(null)"}}

Logs attached.