WebGL Build Failed?

Exception: C:\Program Files\Unity\Editor\Data\il2cpp/build/il2cpp.exe did not run properly! UnityEditorInternal.Runner.RunProgram (UnityEditor.Utils.Program p, System.String exe, System.String args, System.String workingDirectory, UnityEditor.Scripting.Compilers.CompilerOutputParserBase parser) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildUtils.cs:130) UnityEditorInternal.Runner.RunManagedProgram (System.String exe, System.String args, System.String workingDirectory, UnityEditor.Scripting.Compilers.CompilerOutputParserBase parser, System.Action`1 setupStartInfo) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildUtils.cs:73) UnityEditorInternal.IL2CPPBuilder.RunIl2CppWithArguments (System.Collections.Generic.List`1 arguments, System.Action`1 setupStartInfo, System.String workingDirectory) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:336) UnityEditorInternal.IL2CPPBuilder.ConvertPlayerDlltoCpp (ICollection`1 userAssemblies, System.String outputDirectory, System.String workingDirectory) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:317) UnityEditorInternal.IL2CPPBuilder.Run () (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:160) UnityEditorInternal.IL2CPPUtils.RunIl2Cpp (System.String stagingAreaData, IIl2CppPlatformProvider platformProvider, System.Action`1 modifyOutputBeforeCompile, UnityEditor.RuntimeClassRegistry runtimeClassRegistry, Boolean debugBuild) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/Il2Cpp/IL2CPPUtils.cs:41) UnityEditor.WebGL.WebGlBuildPostprocessor.CompileBuild (BuildPostProcessArgs args) (at /Users/builduser/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/BuildPostprocessor.cs:350) UnityEditor.WebGL.WebGlBuildPostprocessor.PostProcess (BuildPostProcessArgs args) (at /Users/builduser/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/BuildPostprocessor.cs:915) UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTargetGroup targetGroup, BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.BuildReporting.BuildReport report) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:272) UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

This is extremely frustrating.

I had a problem about a week ago where I couldn't even open my project and I tried a bunch of things including uninstalling/reinstalling Unity.

Somehow i got that problem fixed, but now I can't build my game to WebGL. If I try to build it as a Windows Executable, it works.

I DID think my hard drive was going to fail the other day so I moved my project and a bunch of other stuff all to one folder to compress and save to a flash drive, but the drive started working right again so I moved the project back out to the Desktop/Unity Projects/ directory.

I don't know what part of any of this broke it.

When I reinstalled Unity, I didn't install all the build platforms like I did the first time, just a few of them this time.

Could that be my problem?