WebGL build issue #10

I opened the project in Unity 2019.3.12f1 and when I try to create a WebGL build, I get the following errors:

Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\CecilUtils.cs(6,13): error CS0234: The type or namespace name 'Cecil' does not exist in the namespace 'Unity' (are you missing an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\InterfaceGen.cs(5,17): error CS0234: The type or namespace name 'Build' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\InterfaceGen.cs(9,13): error CS0234: The type or namespace name 'Entities' does not exist in the namespace 'Unity' (are you missing an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\InterfaceGen.cs(10,13): error CS0234: The type or namespace name 'Cecil' does not exist in the namespace 'Unity' (are you missing an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\TypeRegGen.cs(8,13): error CS0234: The type or namespace name 'Entities' does not exist in the namespace 'Unity' (are you missing an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\TypeRegGen.cs(13,7): error CS0246: The type or namespace name 'Newtonsoft' could not be found (are you missing a using directive or an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\TypeRegGen.cs(64,51): error CS0246: The type or namespace name 'JsonTextWriter' could not be found (are you missing a using directive or an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\TypeRegGen.cs(70,59): error CS0246: The type or namespace name 'JsonTextWriter' could not be found (are you missing a using directive or an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\TypeRegGen.cs(76,58): error CS0246: The type or namespace name 'JsonTextWriter' could not be found (are you missing a using directive or an assembly reference?)
Library\PackageCache\com.unity.dots.runtime@0.25.0-preview\TypeRegGen\TypeRegGen.cs(82,64): error CS0246: The type or namespace name 'JsonTextWriter' could not be found (are you missing a using directive or an assembly reference?)
Error building Player because scripts had compiler errors
Build completed with a result of 'Failed' in 5 seconds (4542 ms)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)
UnityEditor.BuildPlayerWindow+BuildMethodException: 11 errors
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x002bb] in :0
at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x00080] in :0
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Kindly suggest ways to create a successful build