Missing assembly definition in Unity project

[Sov3rain]

Issue Description

Hi,

Omnisharp is telling me that a assembly definition is missing in my script but in fact, Unity has no problem compiling the project.
For those who are familiar with Unity projects, I get this error when I try to access other assemblies located in my /Plugins folder, and in some extent, in any /Editor folder in my project too.

The problem is I don't get any autocompletion, and it's really not convenient. I don't know what is causing this, and I really need some insights.

Steps to Reproduce

Try to access any assembly located in /Plugins or /Editor folder.

Expected Behavior

Actual Behavior

Omnisharp is throwing The type or namespace name 'NativeGallery' could not be found (are you missing a using directive or an assembly reference?) [Assembly-CSharp]

Screenshots

Logs

OmniSharp log

Post the output from Output-->OmniSharp log here

C# log

Post the output from Output-->C# here

Environment information

VSCode version: 1.50.1
C# Extension: 1.23.4

Dotnet Information

.NET Core SDK (reflecting any global.json): Version: 2.1.300 Commit: adab45bf0c

Runtime Environment:
OS Name: Windows
OS Version: 10.0.18363
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\2.1.300\

Host (useful for support):
Version: 3.1.4
Commit: 0c2e69caa6

.NET Core SDKs installed:
2.1.300 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
auto-using	Fudge	0.7.15
awesome-flutter-snippets	Nash	2.0.4
csharp	ms-dotnettools	1.23.4
dart-code	Dart-Code	3.15.1
flutter	Dart-Code	3.15.1
material-icon-theme	PKief	4.3.0
namespace	adrianwilczynski	1.1.2
unity-debug	Unity	2.7.5
unity-tools	Tobiah	1.2.12
vscode-surround	yatki	1.0.2

[ericdrobinson]

This is probably a duplicate of #4113. Please try the workarounds outlined in this comment.

[Sov3rain]

I can confirm that rolling back to Visual Studio Code Editor package version 1.1.3 (sticking to C# for VS Code version 1.23.4) fixed the issue ! Thanks for the hint.

[JoeRobich]

@Sov3rain closing this as a duplicate. Thanks for opening a report.