OmniSharp.MSBuild.ProjectManager Attempted to update project that is not loaded: csharp

Question

Okay, I know that there are already like 100 answers and ways to solve this, but I have tried everything and it just doesn't work.

So here is the error that appears on the console

[fail]: OmniSharp.MSBuild.ProjectManager
        Attempted to update project that is not loaded: c:\Users\Diego\Documents\Programación\Unity\Firs tutorial\Assembly-CSharp.csproj

Here is the csproj file

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <LangVersion>latest</LangVersion>
  </PropertyGroup>
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProductVersion>10.0.20506</ProductVersion>
    <SchemaVersion>2.0</SchemaVersion>
    <RootNamespace></RootNamespace>
    <ProjectGuid>{4500960e-2db2-a8c2-56e1-0b4aaa9f3d70}</ProjectGuid>
    <OutputType>Library</OutputType>
    <AppDesignerFolder>Properties</AppDesignerFolder>
    <AssemblyName>Assembly-CSharp</AssemblyName>
    <TargetFrameworkVersion>v4.7.1</TargetFrameworkVersion>
    <FileAlignment>512</FileAlignment>
    <BaseDirectory>.</BaseDirectory>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>Temp\bin\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE;UNITY_2020_3_2;UNITY_2020_3;UNITY_2020;UNITY_5_3_OR_NEWER;UNITY_5_4_OR_NEWER;UNITY_5_5_OR_NEWER;UNITY_5_6_OR_NEWER;UNITY_2017_1_OR_NEWER;UNITY_2017_2_OR_NEWER;UNITY_2017_3_OR_NEWER;UNITY_2017_4_OR_NEWER;UNITY_2018_1_OR_NEWER;UNITY_2018_2_OR_NEWER;UNITY_2018_3_OR_NEWER;UNITY_2018_4_OR_NEWER;UNITY_2019_1_OR_NEWER;UNITY_2019_2_OR_NEWER;UNITY_2019_3_OR_NEWER;UNITY_2019_4_OR_NEWER;UNITY_2020_1_OR_NEWER;UNITY_2020_2_OR_NEWER;UNITY_2020_3_OR_NEWER;UNITY_INCLUDE_TESTS;USE_SEARCH_ENGINE_API;SCENE_TEMPLATE_MODULE;ENABLE_AR;ENABLE_AUDIO;ENABLE_CACHING;ENABLE_CLOTH;ENABLE_EVENT_QUEUE;ENABLE_MICROPHONE;ENABLE_MULTIPLE_DISPLAYS;ENABLE_PHYSICS;ENABLE_TEXTURE_STREAMING;ENABLE_VIRTUALTEXTURING;ENABLE_UNET;ENABLE_LZMA;ENABLE_UNITYEVENTS;ENABLE_VR;ENABLE_WEBCAM;ENABLE_UNITYWEBREQUEST;ENABLE_WWW;ENABLE_CLOUD_SERVICES;ENABLE_CLOUD_SERVICES_COLLAB;ENABLE_CLOUD_SERVICES_COLLAB_SOFTLOCKS;ENABLE_CLOUD_SERVICES_ADS;ENABLE_CLOUD_SERVICES_USE_WEBREQUEST;ENABLE_CLOUD_SERVICES_CRASH_REPORTING;ENABLE_CLOUD_SERVICES_PURCHASING;ENABLE_CLOUD_SERVICES_ANALYTICS;ENABLE_CLOUD_SERVICES_UNET;ENABLE_CLOUD_SERVICES_BUILD;ENABLE_CLOUD_LICENSE;ENABLE_EDITOR_HUB_LICENSE;ENABLE_WEBSOCKET_CLIENT;ENABLE_DIRECTOR_AUDIO;ENABLE_DIRECTOR_TEXTURE;ENABLE_MANAGED_JOBS;ENABLE_MANAGED_TRANSFORM_JOBS;ENABLE_MANAGED_ANIMATION_JOBS;ENABLE_MANAGED_AUDIO_JOBS;INCLUDE_DYNAMIC_GI;ENABLE_MONO_BDWGC;ENABLE_SCRIPTING_GC_WBARRIERS;PLATFORM_SUPPORTS_MONO;RENDER_SOFTWARE_CURSOR;ENABLE_VIDEO;PLATFORM_STANDALONE;PLATFORM_STANDALONE_WIN;UNITY_STANDALONE_WIN;UNITY_STANDALONE;ENABLE_RUNTIME_GI;ENABLE_MOVIES;ENABLE_NETWORK;ENABLE_CRUNCH_TEXTURE_COMPRESSION;ENABLE_OUT_OF_PROCESS_CRASH_HANDLER;ENABLE_CLUSTER_SYNC;ENABLE_CLUSTERINPUT;PLATFORM_UPDATES_TIME_OUTSIDE_OF_PLAYER_LOOP;GFXDEVICE_WAITFOREVENT_MESSAGEPUMP;ENABLE_WEBSOCKET_HOST;ENABLE_MONO;NET_STANDARD_2_0;ENABLE_PROFILER;UNITY_ASSERTIONS;UNITY_EDITOR;UNITY_EDITOR_64;UNITY_EDITOR_WIN;ENABLE_UNITY_COLLECTIONS_CHECKS;ENABLE_BURST_AOT;UNITY_TEAM_LICENSE;ENABLE_CUSTOM_RENDER_TEXTURE;ENABLE_DIRECTOR;ENABLE_LOCALIZATION;ENABLE_SPRITES;ENABLE_TERRAIN;ENABLE_TILEMAP;ENABLE_TIMELINE;ENABLE_LEGACY_INPUT_MANAGER;CSHARP_7_OR_LATER;CSHARP_7_3_OR_NEWER</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <NoWarn>0169</NoWarn>
    <AllowUnsafeBlocks>False</AllowUnsafeBlocks>
  </PropertyGroup>
  <PropertyGroup>
    <NoConfig>true</NoConfig>
    <NoStdLib>true</NoStdLib>
    <AddAdditionalExplicitAssemblyReferences>false</AddAdditionalExplicitAssemblyReferences>
    <ImplicitlyExpandNETStandardFacades>false</ImplicitlyExpandNETStandardFacades>
    <ImplicitlyExpandDesignTimeFacades>false</ImplicitlyExpandDesignTimeFacades>
  </PropertyGroup>

I have downloaded probably like ten times the dot net SDKs and frameworks and it just doesn't work. There is like 1 million possible sources for these problems and I just need some help, please. I have been trying to solve this for days now and I just can't, I would extremely appreciate it if someone could help me out.

Answer 1

In the VS Code menu, go into File / Preferences / Settings.
In the "Search settings" window, type omnisharp.path
Click on "Edit in settings.json" link.
Add (or edit) like this: "omnisharp.path": "latest"

Also, another question: what OS are you using? The proj file that you posted is in legacy format, not in SDK format, and I have doubts if it is compliable outside of Windows. It is fairly easy to convert to SDK:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <LangVersion>latest</LangVersion>
    <TargetFramework>net471</TargetFramework>
    <WarningLevel>4</WarningLevel>
    <NoWarn>0169</NoWarn>
    <NoConfig>true</NoConfig>
    <NoStdLib>true</NoStdLib>
    <AddAdditionalExplicitAssemblyReferences>false</AddAdditionalExplicitAssemblyReferences>
    <ImplicitlyExpandNETStandardFacades>false</ImplicitlyExpandNETStandardFacades>
    <ImplicitlyExpandDesignTimeFacades>false</ImplicitlyExpandDesignTimeFacades>
  </PropertyGroup>
</Project>

or you can just create from scratch with new project template using dotnet new or Visual Studio (may be there are plugins for VSCode as well)