VS activity log gives this error when I try using ctrl+j:

  <entry>
    <record>964</record>
    <time>2018/07/01 12:30:51.397</time>
    <type>Error</type>
    <source>Editor or Editor Extension</source>
    <description>System.IO.DirectoryNotFoundException: The system cannot find the path specified. (Exception from HRESULT: 0x80070003)&#x000D;&#x000A;   at Microsoft.VisualStudio.CppSvc.Internal.IVCTextEdit.GoToDefinition(String wszFilePath, Int32 iPosStart, Int32 iPosEnd, VCSymbolCommand cmd)&#x000D;&#x000A;   at Microsoft.VisualC.CppNavigableSymbol.Navigate(INavigableRelationship relationship)&#x000D;&#x000A;   at PreprocessMouseUp(MouseButtonEventArgs e)&#x000D;&#x000A;--- End of stack trace from previous location where exception was thrown ---&#x000D;&#x000A;   at ExceptionInfo(Exception exceptionObject)</description>
  </entry> 

It's odd because it's only missing from arduino projects. Working fine in regular C++ and Python projects.

I found the problem with the latest vs updates and will report to Microsoft.

I suspect that if you switch the tool bar from Debug to Release your project intellisense will work

The problem is that if a PlatformToolset is not specified for the current configuration Visual Studio fails to read the project properties.

You can fix this yourself by editing your vcxproj file with a text editor. 

Notice in the .vcxproj snippet below the <PlatformToolset> is specified for Release but not for the Debug configuration. Add <PlatformToolset>v141</PlatformToolset> to any configs that do not specify one.

Save the vcxproj and reopen the project in Visual Studio and the issue should be resolved.

<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
    <ConfigurationType>Application</ConfigurationType>
    <UseDebugLibraries>false</UseDebugLibraries>
    <PlatformToolset>v141</PlatformToolset>
    <WholeProgramOptimization>true</WholeProgramOptimization>
    <CharacterSet>MultiByte</CharacterSet>
  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
    <ConfigurationType>Application</ConfigurationType>
    <UseDebugLibraries>true</UseDebugLibraries>
    <CharacterSet>MultiByte</CharacterSet>
  </PropertyGroup> 

Hi

I have explained the fix and reported the bug to microsoft.

Did my previous message not make sense? It's an easy fix to edit the vcxproj file.

I suspect my explanation confused.

There is a new release of visual micro in the gallery and better explanation to fix in the release notes

After fixing see if you can right click the name of the project and then click "Properties". If the property pages dialog opens then you have fixed this issue. If intellisense still fails then please email your .vcxproj file to info[at]visualmicro.com along with link to this post

Thanks

Pls send the vcxproj file as requested.

Thanks

Thanks. The Test.vcxproj only contains Test.ino.

Does intellisense work in Test.ino?

Hot damn, I found the solution. Microsoft even managed to screw up Linux integration. I was using WSL to handle git and apparently it screws up case sensitivity for the entire folder structure. So the way the fix it was to delete the entire Arduino folder and recreate it, install user libraries again, go back to git bash and voilà, everything is normal. Good news is that it had nothing to do with Visual Micro. I just wish there was a Teensy support in vscode so I could go back to Linux.

The issue report is here https://github.com/Microsoft/WSL/issues/2937