diff --git a/.github/workflows/copilot-setup-steps.yml b/.github/workflows/copilot-setup-steps.yml
index abef568c5c5..5091aec9f0d 100644
--- a/.github/workflows/copilot-setup-steps.yml
+++ b/.github/workflows/copilot-setup-steps.yml
@@ -18,7 +18,15 @@ jobs:
       - uses: actions/setup-dotnet@v4
         with:
           global-json-file: global.json
-      - name: Restore solution
+      - name: Restore the compiler service solution
         env:
           CI: false
         run: dotnet build ./FSharp.Compiler.Service.sln --verbosity quiet
+      - name: Restore the language server solution
+        env:
+          CI: false
+        run: dotnet build ./VSFSharpExtension.sln --verbosity quiet
+      - name: Restore dotnet tools
+        env:
+          CI: false
+        run: dotnet tool restore
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 7b17d64c652..5e098d1702b 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -40,25 +40,25 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>12d3a9f5d6138e22270694574e73e4c58a815795</Sha>
     </Dependency>
-    <Dependency Name="optimization.windows_nt-x64.MIBC.Runtime" Version="1.0.0-prerelease.25304.1">
+    <Dependency Name="optimization.windows_nt-x64.MIBC.Runtime" Version="1.0.0-prerelease.25309.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>
-      <Sha>3209c82631372c33b3df04636ab2a6fd255b0681</Sha>
+      <Sha>b1f3f5c40f86362217f1b98952d5c6562d609619</Sha>
     </Dependency>
-    <Dependency Name="optimization.windows_nt-x86.MIBC.Runtime" Version="1.0.0-prerelease.25304.1">
+    <Dependency Name="optimization.windows_nt-x86.MIBC.Runtime" Version="1.0.0-prerelease.25309.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>
-      <Sha>3209c82631372c33b3df04636ab2a6fd255b0681</Sha>
+      <Sha>b1f3f5c40f86362217f1b98952d5c6562d609619</Sha>
     </Dependency>
-    <Dependency Name="optimization.linux-x64.MIBC.Runtime" Version="1.0.0-prerelease.25304.1">
+    <Dependency Name="optimization.linux-x64.MIBC.Runtime" Version="1.0.0-prerelease.25309.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>
-      <Sha>3209c82631372c33b3df04636ab2a6fd255b0681</Sha>
+      <Sha>b1f3f5c40f86362217f1b98952d5c6562d609619</Sha>
     </Dependency>
-    <Dependency Name="optimization.windows_nt-arm64.MIBC.Runtime" Version="1.0.0-prerelease.25304.1">
+    <Dependency Name="optimization.windows_nt-arm64.MIBC.Runtime" Version="1.0.0-prerelease.25309.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>
-      <Sha>3209c82631372c33b3df04636ab2a6fd255b0681</Sha>
+      <Sha>b1f3f5c40f86362217f1b98952d5c6562d609619</Sha>
     </Dependency>
-    <Dependency Name="optimization.linux-arm64.MIBC.Runtime" Version="1.0.0-prerelease.25304.1">
+    <Dependency Name="optimization.linux-arm64.MIBC.Runtime" Version="1.0.0-prerelease.25309.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>
-      <Sha>3209c82631372c33b3df04636ab2a6fd255b0681</Sha>
+      <Sha>b1f3f5c40f86362217f1b98952d5c6562d609619</Sha>
     </Dependency>
   </ToolsetDependencies>
 </Dependencies>
diff --git a/eng/Versions.props b/eng/Versions.props
index 27383527757..34e62fdd415 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -97,7 +97,7 @@
     <SystemThreadingTasksDataflow>$(SystemPackageVersionVersion)</SystemThreadingTasksDataflow>
     <MicrosoftDiaSymReaderPortablePdbVersion>1.6.0</MicrosoftDiaSymReaderPortablePdbVersion>
     <!-- Versions for package groups -->
-    <RoslynVersion>4.15.0-1.25171.14</RoslynVersion>
+    <RoslynVersion>5.0.0-1.25276.102</RoslynVersion>
     <VisualStudioEditorPackagesVersion>17.14.188</VisualStudioEditorPackagesVersion>
     <MicrosoftVisualStudioShellPackagesVersion>17.14.40268</MicrosoftVisualStudioShellPackagesVersion>
     <VisualStudioProjectSystemPackagesVersion>17.14.79</VisualStudioProjectSystemPackagesVersion>
@@ -105,9 +105,10 @@
     <MicrosoftVisualStudioThreadingPackagesVersion>17.14.15</MicrosoftVisualStudioThreadingPackagesVersion>
     <MicrosoftBuildVersion>17.15.0-preview-25278-01</MicrosoftBuildVersion>
     <!-- Roslyn packages -->
+    <MicrosoftCodeAnalysisFeaturesVersion>$(RoslynVersion)</MicrosoftCodeAnalysisFeaturesVersion>
     <MicrosoftCodeAnalysisEditorFeaturesVersion>$(RoslynVersion)</MicrosoftCodeAnalysisEditorFeaturesVersion>
     <MicrosoftCodeAnalysisEditorFeaturesTextVersion>$(RoslynVersion)</MicrosoftCodeAnalysisEditorFeaturesTextVersion>
-    <MicrosoftCodeAnalysisEditorFeaturesWpfVersion>$(RoslynVersion)</MicrosoftCodeAnalysisEditorFeaturesWpfVersion>
+    <MicrosoftCodeAnalysisEditorFeaturesWpfVersion>5.0.0-1.25275.2</MicrosoftCodeAnalysisEditorFeaturesWpfVersion>
     <MicrosoftCodeAnalysisExternalAccessFSharpVersion>$(RoslynVersion)</MicrosoftCodeAnalysisExternalAccessFSharpVersion>
     <MicrosoftCodeAnalysisVersion>$(RoslynVersion)</MicrosoftCodeAnalysisVersion>
     <MicrosoftCodeAnalysisCSharpVersion>$(RoslynVersion)</MicrosoftCodeAnalysisCSharpVersion>
@@ -204,10 +205,10 @@
     <HumanizerCoreVersion>2.2.0</HumanizerCoreVersion>
     <!-- -->
     <!-- MIBC profile packages -->
-    <optimizationwindows_ntx64MIBCRuntimeVersion>1.0.0-prerelease.25304.1</optimizationwindows_ntx64MIBCRuntimeVersion>
-    <optimizationwindows_ntx86MIBCRuntimeVersion>1.0.0-prerelease.25304.1</optimizationwindows_ntx86MIBCRuntimeVersion>
-    <optimizationwindows_ntarm64MIBCRuntimeVersion>1.0.0-prerelease.25304.1</optimizationwindows_ntarm64MIBCRuntimeVersion>
-    <optimizationlinuxx64MIBCRuntimeVersion>1.0.0-prerelease.25304.1</optimizationlinuxx64MIBCRuntimeVersion>
-    <optimizationlinuxarm64MIBCRuntimeVersion>1.0.0-prerelease.25304.1</optimizationlinuxarm64MIBCRuntimeVersion>
+    <optimizationwindows_ntx64MIBCRuntimeVersion>1.0.0-prerelease.25309.1</optimizationwindows_ntx64MIBCRuntimeVersion>
+    <optimizationwindows_ntx86MIBCRuntimeVersion>1.0.0-prerelease.25309.1</optimizationwindows_ntx86MIBCRuntimeVersion>
+    <optimizationwindows_ntarm64MIBCRuntimeVersion>1.0.0-prerelease.25309.1</optimizationwindows_ntarm64MIBCRuntimeVersion>
+    <optimizationlinuxx64MIBCRuntimeVersion>1.0.0-prerelease.25309.1</optimizationlinuxx64MIBCRuntimeVersion>
+    <optimizationlinuxarm64MIBCRuntimeVersion>1.0.0-prerelease.25309.1</optimizationlinuxarm64MIBCRuntimeVersion>
   </PropertyGroup>
 </Project>
diff --git a/vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj b/vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj
index fbafe3bd839..8ccba61a5af 100644
--- a/vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj
+++ b/vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj
@@ -6,6 +6,7 @@
     <OutputType>Library</OutputType>
     <NoWarn>$(NoWarn);75</NoWarn>
     <NoWarn>$(NoWarn);44</NoWarn><!-- warning about Roslyn API only for F# and TypeScript -->
+    <NoWarn>$(NoWarn);NU1608</NoWarn> <!-- warning about package downgrade -->
     <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
     <OtherFlags>$(OtherFlags) --subsystemversion:6.00</OtherFlags>
     <EnableDefaultEmbeddedResourceItems>false</EnableDefaultEmbeddedResourceItems>
@@ -172,10 +173,11 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.Features" Version="$(MicrosoftCodeAnalysisFeaturesVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
     <PackageReference Include="Microsoft.VisualStudio.Interop" Version="$(MicrosoftVisualStudioInteropVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
     <PackageReference Include="Microsoft.Internal.VisualStudio.Interop" Version="$(MicrosoftInternalVisualStudioInteropVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
     <PackageReference Include="Microsoft.CodeAnalysis.EditorFeatures.Text" Version="$(MicrosoftCodeAnalysisEditorFeaturesTextVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
-    <PackageReference Include="Microsoft.CodeAnalysis.EditorFeatures.Wpf" Version="$(MicrosoftCodeAnalysisEditorFeaturesWpfVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
+    <PackageReference Include="Microsoft.CodeAnalysis.EditorFeatures.Wpf" Version="$(MicrosoftCodeAnalysisEditorFeaturesWpfVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" NoWarn="NU1608" />
     <PackageReference Include="Microsoft.CodeAnalysis.ExternalAccess.FSharp" Version="$(MicrosoftCodeAnalysisExternalAccessFSharpVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
     <PackageReference Include="Microsoft.Composition" Version="$(MicrosoftCompositionVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
     <PackageReference Include="Microsoft.VisualStudio.ComponentModelHost" Version="$(MicrosoftVisualStudioComponentModelHostVersion)" PrivateAssets="all" ExcludeAssets="runtime;contentFiles;build;analyzers;native" />
diff --git a/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs b/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
index 4f6136b8db0..b7e34648aed 100644
--- a/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
+++ b/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
@@ -355,12 +355,12 @@ type internal FSharpPackage() as this =
             flushTelemetry ()
 #endif
 
-    override this.RegisterInitializationWork(packageRegistrationTasks: PackageRegistrationTasks) : unit =
-        base.RegisterInitializationWork(packageRegistrationTasks: PackageRegistrationTasks)
+    override this.RegisterInitializeAsyncWork(packageRegistrationTasks: PackageLoadTasks) : unit =
+        base.RegisterInitializeAsyncWork(packageRegistrationTasks)
 
         packageRegistrationTasks.AddTask(
             true,
-            (fun progress _tasks cancellationToken ->
+            (fun _tasks cancellationToken ->
                 foregroundCancellableTask {
                     let! commandService = this.GetServiceAsync(typeof<IMenuCommandService>)
                     let commandService = commandService :?> OleMenuCommandService