I was able to open Rider with this

Author: nojaf

ReSharper.FSharp/Directory.Build.props

@@ -34,11 +34,13 @@
     <RdBackendCommonSubplatform>$(Subplatform).Rider_RdBackend.Common.Props</RdBackendCommonSubplatform>
     <RiderBackendSubplatform>$(Subplatform).Rider_Rider.Backend.Props</RiderBackendSubplatform>
     <UseLocalFSharpCompilerService>true</UseLocalFSharpCompilerService>
-    <LocalFCSProject>$(MSBuildThisFileDirectory)../../fsharp/src/Compiler/FSharp.Compiler.Service.fsproj</LocalFCSProject>
+    <LocalFSharpRepository>$(MSBuildThisFileDirectory)../../fsharp</LocalFSharpRepository>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Condition="'$(UseLocalFSharpCompilerService)' == 'false'" Include="JetBrains.FSharp.Compiler.Service" />
-    <ProjectReference Condition="'$(UseLocalFSharpCompilerService)' == 'true'" Include="$(LocalFCSProject)" />
+    <ProjectReference Condition="'$(UseLocalFSharpCompilerService)' == 'true'" Include="$(LocalFSharpRepository)/src/Compiler/FSharp.Compiler.Service.fsproj" />
+    <ProjectReference Condition="'$(UseLocalFSharpCompilerService)' == 'true'" Include="$(LocalFSharpRepository)/src/FSharp.Compiler.Interactive.Settings/FSharp.Compiler.Interactive.Settings.fsproj" />
+    <ProjectReference Condition="'$(UseLocalFSharpCompilerService)' == 'true'" Include="$(LocalFSharpRepository)/src/FSharp.DependencyManager.Nuget/FSharp.DependencyManager.Nuget.fsproj" />
   </ItemGroup>
 </Project>

ReSharper.FSharp/src/FSharp/FSharp.Common/src/Checker/FcsCheckerService.fs

@@ -99,7 +99,8 @@ type FcsCheckerService(lifetime: Lifetime, logger: ILogger, onSolutionCloseNotif
         let setting = SettingsUtil.getEntry<FSharpOptions> settingsStore name
         settingsStoreLive.GetValueProperty(lifetime, setting, null)
 
-    let useTransparentCompiler = (getSettingProperty "UseTransparentCompiler").Value
+    let useTransparentCompiler = true
+        // (getSettingProperty "UseTransparentCompiler").Value
 
     let checker =
         Environment.SetEnvironmentVariable("FCS_CheckFileInProjectCacheSize", "20")