Win32Exception thrown on Build and Run with WebGL2.0 Graphics API due to mono.exe is missing when WebGL supports installing from Download assistant

Steps to Reproduce:

1. Create a new Project
2. Switch Platform to WebGL
3. Uncheck PlayerSettings > Other Settings > Auto Graphic API
4. Select WebGL 2.0 Graphics API
5. Click on Build Settings > Build and Run

Expected Result:
Build runs on Browser

Actual Result:
Win32Exception thrown

Reproducible on: 2020.1.0a15, 2019.3.0f1

Working Fine on: 2020.1.0a14, 2019.3.0b12

Environment: Windows 10 with AMD Radeon R9 200 Series only

Note: Graphics card detail is attached

Stack Trace:

Win32Exception: ApplicationName='"D:/Unity/Unity 2019.3.0f1/Editor/Data/MonoBleedingEdge/bin/mono.exe"', CommandLine='"D:/Unity/Unity 2019.3.0f1/Editor/Data/PlaybackEngines/WebGLSupport/BuildTools/SimpleWebServer.exe" "D:/NishantWork/PRChanges/New Unity Project/New folder (2)" 50393 12788 gzip', CurrentDirectory='D:/NishantWork/PRChanges/New Unity Project/Assets/..', Native error= The system cannot find the file specified.

System.Diagnostics.Process.StartWithCreateProcess (System.Diagnostics.ProcessStartInfo startInfo) (at <ae22a4e8f83c41d69684ae7f557133d9>:0)
System.Diagnostics.Process.Start () (at <ae22a4e8f83c41d69684ae7f557133d9>:0)
(wrapper remoting-invoke-with-check) System.Diagnostics.Process.Start()
UnityEditor.WebGL.HttpServerEditorWrapper.Create (System.String _path, System.String _wasmEncoding, System.Int32 _port) (at /Users/builduser/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/HttpServerEditorWrapper.cs:24)
UnityEditor.WebGL.HttpServerEditorWrapper.CreateIfNeeded (System.String path, System.String wasmEncoding, System.Int32& port) (at /Users/builduser/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/HttpServerEditorWrapper.cs:95)
UnityEditor.WebGL.WebGlBuildPostprocessor.LaunchPlayer (UnityEditor.Modules.BuildLaunchPlayerArgs args) (at /Users/builduser/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/BuildPostprocessor.cs:343)
UnityEditor.PostprocessBuildPlayer.Launch (UnityEditor.BuildTargetGroup targetGroup, UnityEditor.BuildTarget buildTarget, System.String path, System.String productName, UnityEditor.BuildOptions options, UnityEditor.Build.Reporting.BuildReport buildReport) (at <3b74787e58694cdda2c241162159b3b7>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)