Intellisense broken in latest stable Xamarin iOS after updating to XCode 8.3.1

Question

My iOS application was being built on a build machine running xCode 7.x up until recently. Now we're preparing a build with xCode 8.3.1. The latest Xamarin Studio iOS stable with xCode 8.3.1 seems think all of my code is invalid. Pretty much every class and every line has some sort of error despite the code being fully compilable and deploying. Notice the syntax bar on the far right of the screenshot is solid red. This was not happening, before updating to the latest stable Xamarin Studio and xCode.

Xamarin versions:

Xamarin Studio Community
Version 6.3 (build 863)
Installation UUID: 87149f4b-0f09-4f27-8133-582330f3df28
Runtime:
    Mono 4.8.1 (mono-4.8.0-branch/22a39d7) (64-bit)
    GTK+ 2.24.23 (Raleigh theme)

    Package version: 408010000

NuGet
Version: 3.5.0.0

Xamarin.Profiler
Version: 1.4.0
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

Apple Developer Tools
Xcode 8.3.1 (12170)
Build 8E1000a

Xamarin.Android
Version: 7.2.0.7 (Xamarin Studio Community)
Android SDK: /Users/joeyz/Library/Developer/Xamarin/android-sdk-macosx
    Supported Android versions:
        5.0 (API level 21)
        6.0 (API level 23)
        7.0 (API level 24)
        7.1 (API level 25)

SDK Tools Version: 25.2.5
SDK Platform Tools Version: 25.0.4
SDK Build Tools Version: 25.0.2

Java SDK: /usr
java version "1.8.0_101"
Java(TM) SE Runtime Environment (build 1.8.0_101-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.101-b13, mixed mode)

Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

Xamarin.Mac
Version: 3.2.0.175 (Xamarin Studio Community)

Xamarin.iOS
Version: 10.8.0.175 (Xamarin Studio Community)
Hash: a04678c2
Branch: d15-1
Build date: 2017-03-28 14:05:38-0400

Xamarin Inspector
Version: 1.2.2
Hash: b71b035
Branch: d15-1
Build date: Fri, 21 Apr 2017 17:57:12 GMT

Build Information
Release ID: 603000863
Git revision: a2163670efe259c85cd8f335d95b175068fbbe2a
Build date: 2017-04-03 14:33:15-04
Xamarin addins: 2045d688ea1420e0381b473360ca62a763eb7d04
Build lane: monodevelop-lion-d15-1

Operating System
Mac OS X 10.12.4
Darwin Pako-2.local 16.5.0 Darwin Kernel Version 16.5.0
    Fri Mar  3 16:52:33 PST 2017
    root:xnu-3789.51.2~3/RELEASE_X86_64 x86_64

Edit:

So Visual Studio for mac is having the same problem with intellisense. Only difference is it's actually giving me an error for each red line (unlike Xamarin Studio which builds regardless of the red lines). It doesn't make any sense. For example it's saying "Predefined type 'System.Booleon' is not defined or implemented" despite me having "using System;"

r.com/Aahaf.png

Answer 1

I recall an old bug that was listed in 2014, I couldn't find the bugzilla link, but essentially it noted the same problem for local builds and I think there was one individual who highlighted a similar issue for automated builds. One of the early work around was to roll Xamarin back to an older version and update, or alternatively remove and reinstall. It's not remotely practical but it should resolve the issue. It's entirely possible that removing certain cache files will also solve the problem, but it's hard to determine precisely which ones relate to this issue.

Edit:

So I've taken some time to look for a few various fixes that might help solve the problem, Obviously I don't know exactly the kind of set up you have on your build machine, but here are a few tried and tested ways to resolve general intellisense issues.

1. Ensure "Auto List Members" and "Parameter Information" are both ticked, found in : Tools -> Options -> Text Editor -> All Languages -> General

2. Just delete the folder "ReflectedSchemas". The location depends on the Visual Studio Version being used, but it's generally in this area: %AppData%\Microsoft\VisualStudio\11.0\ReflectedSchemas

3. Reset settings in VS : Tools->Import and Export settings->Reset all settings.

4. Refresh the intellisense local cache : Edit -> Intellisense -> Refresh Local Cache

5. Delete the Psess file in your project.

Theses are all valid ways to try and restore intellisense information back to it's correct state. They are more of a blanket approach of things to try. Give me a shout if none of these work and we will try to think of some more.