Hi all,
I've been suffering from this problem for a long time (the last working version of Xamarin.Android for me was xamarin.android-8.0.2 (I still have the package in my downloads folder as I've had to go back to it every whenever I update Xamarin through the updater). But with the latest stable release, that version of xam.droid is not really compatible at all with the newest Visual Studio (mac), and I haven't found a link to downgrade VS, so I'm quick stuck now (and have spent many hours today trying everything, EVERYTHING to make it work).
Basically whenever I try to open the designer I get the following error:
[2018-03-06 17:39:45.6] Renderer >> ERROR: Failed to process message LoadProject [2018-03-06 17:39:45.6] Renderer >> ERROR: java.lang.NullPointerException: at index 0 [2018-03-06 17:39:45.6] Renderer >> at com.google.common.collect.ObjectArrays.checkElementNotNull(ObjectArrays.java:239) [2018-03-06 17:39:45.6] Renderer >> at com.google.common.collect.ObjectArrays.checkElementsNotNull(ObjectArrays.java:230) [2018-03-06 17:39:45.6] Renderer >> at com.google.common.collect.ObjectArrays.checkElementsNotNull(ObjectArrays.java:225) [2018-03-06 17:39:45.6] Renderer >> at com.google.common.collect.ImmutableList.copyOf(ImmutableList.java:273) [2018-03-06 17:39:45.6] Renderer >> at mono.android.Project.<init>(Project.java:63) [2018-03-06 17:39:45.6] Renderer >> at mono.android.AndroidDesignerHost.loadProject(AndroidDesignerHost.java:238) [2018-03-06 17:39:45.6] Renderer >> at mono.android.AndroidDesignerHost.processMessage(AndroidDesignerHost.java:265) [2018-03-06 17:39:45.6] Renderer >> at mono.android.MessageListener.executeMessage(MessageListener.java:88) [2018-03-06 17:39:45.6] Renderer >> at mono.android.MessageListener$Runner.run(MessageListener.java:44) [2018-03-06 17:39:45.6] Renderer >> at java.lang.Thread.run(Thread.java:745) [2018-03-06 17:39:45.6] Renderer >> [2018-03-06 17:39:45.6] ERROR: : Project load failed Xamarin.AndroidDesigner.Java.JavaErrorMessageException: The operation LoadProject failed due to an internal error: at index 0. at Xamarin.AndroidDesigner.Java.JavaProcessConnection+<GetResponse>d__53.MoveNext () [0x000e1] in /Users/vsts/agent/2.129.1/work/1/s/Xamarin.Designer.Android/Xamarin.AndroidDesigner/Xamarin.AndroidDesigner.Java/JavaProcessConnection.cs:260 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 at System.Runtime.CompilerServices.TaskAwaiter1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:357
at Xamarin.AndroidDesigner.DesignerProject+d__172.MoveNext () [0x002a9] in /Users/vsts/agent/2.129.1/work/1/s/Xamarin.Designer.Android/Xamarin.AndroidDesigner/Xamarin.AndroidDesigner/DesignerProject.cs:905
[2018-03-06 17:39:45.6] ERROR: : Session initialization failed
Xamarin.AndroidDesigner.Java.JavaErrorMessageException: The operation LoadProject failed due to an internal error: at index 0.
at Xamarin.AndroidDesigner.Java.JavaProcessConnection+d__53.MoveNext () [0x000e1] in /Users/vsts/agent/2.129.1/work/1/s/Xamarin.Designer.Android/Xamarin.AndroidDesigner/Xamarin.AndroidDesigner.Java/JavaProcessConnection.cs:260
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.TaskAwaiter1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:357 at Xamarin.AndroidDesigner.DesignerProject+<EnsureLoaded>d__172.MoveNext () [0x003da] in /Users/vsts/agent/2.129.1/work/1/s/Xamarin.Designer.Android/Xamarin.AndroidDesigner/Xamarin.AndroidDesigner/DesignerProject.cs:912 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 at System.Runtime.CompilerServices.TaskAwaiter1[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/5533/mono-mac-sdk/external/bockbuild/builds/mono-x64/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:357
at Xamarin.AndroidDesigner.AndroidRenderSession+d__113.MoveNext () [0x00182] in /Users/vsts/agent/2.129.1/work/1/s/Xamarin.Designer.Android/Xamarin.AndroidDesigner/Xamarin.AndroidDesigner/AndroidRenderSession.cs:711
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