UnityにアツマールAPIforUnityを導入後、ビルド不能に

よろしくお願いします。

前提

Unityでゲームを作っています（C#）。
アツマールAPIforUnityを導入したところ、ビルドが失敗するようになりました。
https://sinoa-dev.gitbook.io/rpgatsumaruapiforunity/build-environment/install-library

正確には導入後、シーンにAPIに必須のプラグインの初期化
https://sinoa-dev.gitbook.io/rpgatsumaruapiforunity/sample-api/sample-code-list/initialize-api
を記述すると、webGLビルドに失敗します。
該当部分をコメントアウトすると成功します。

Unityエディターバージョンは2021.2.3f1です。

実現したいこと

ビルドが成功するようにしたい。

発生している問題・エラーメッセージ

Building Library\Bee\artifacts\WebGL\build\debug_WebGL_wasm\build.js failed with output:
Traceback (most recent call last):
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emcc2.py", line 3571, in <module>
    sys.exit(main(sys.argv))
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emcc2.py", line 3564, in main
    ret = run(args)
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emcc2.py", line 1082, in run
    phase_post_link(options, wasm_target, wasm_target, target)
  File "D:\obj\windows-release\37amd64_Release\msi_python\zip_amd64\contextlib.py", line 74, in inner
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emcc2.py", line 2400, in phase_post_link
    phase_emscript(options, in_wasm, wasm_target, memfile)
  File "D:\obj\windows-release\37amd64_Release\msi_python\zip_amd64\contextlib.py", line 74, in inner
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emcc2.py", line 2428, in phase_emscript
    emscripten.run(in_wasm, wasm_target, final_js, memfile)
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emscripten.py", line 830, in run
    emscript(in_wasm, out_wasm, outfile_js, memfile, shared.DEBUG)
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emscripten.py", line 308, in emscript
    glue, forwarded_data = compile_settings()
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\emscripten.py", line 178, in compile_settings
    cwd=path_from_root('src'), env=env)
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\tools\shared.py", line 216, in run_js_tool
    return check_call(command, *args, **kw).stdout
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\tools\shared.py", line 202, in check_call
    return run_process(cmd, *args, **kw)
  File "C:\Program Files\Unity\Hub\Editor\2021.2.3f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emscripten\tools\shared.py", line 97, in run_process
    ret = subprocess.run(cmd, check=check, input=input, *args, **kw)
  File "D:\obj\windows-release\37amd64_Release\msi_python\zip_amd64\subprocess.py", line 474, in run
  File "D:\obj\windows-release\37amd64_Release\msi_python\zip_amd64\subprocess.py", line 926, in communicate
UnicodeDecodeError: 'cp932' codec can't decode byte 0x87 in position 52557: illegal multibyte sequence
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun ()

BuildFailedException: Incremental Player build failed!
UnityEditor.Modules.BeeBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args) (at <ba030cc3475e41258f58c8c467eb72e2>:0)
UnityEditor.WebGL.WebGlBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args) (at /Users/bokken/buildslave/unity/build/PlatformDependent/WebGL/Extensions/Unity.WebGL.extensions/BuildPostprocessor.cs:157)
UnityEditor.Modules.DefaultBuildPostprocessor.PostProcess (UnityEditor.Modules.BuildPostProcessArgs args, UnityEditor.BuildProperties& outProperties) (at <ba030cc3475e41258f58c8c467eb72e2>:0)
UnityEditor.PostprocessBuildPlayer.Postprocess (UnityEditor.BuildTargetGroup targetGroup, UnityEditor.BuildTarget target, System.Int32 subtarget, System.String installPath, System.String companyName, System.String productName, System.Int32 width, System.Int32 height, UnityEditor.BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry, UnityEditor.Build.Reporting.BuildReport report) (at <ba030cc3475e41258f58c8c467eb72e2>:0)
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()

Build completed with a result of 'Failed' in 78 seconds (78259 ms)
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun ()

UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors
  at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x002d8] in <ba030cc3475e41258f58c8c467eb72e2>:0 
  at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x00080] in <ba030cc3475e41258f58c8c467eb72e2>:0 
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun ()

該当のソースコード

C#
1using RpgAtsumaruApiForUnity;
2using UnityEngine;
3
4public class RpgAtsumaruSample : MonoBehaviour
5{
6    private void Awake()
7    {
8        // もしプラグインの初期化が終わっていないなら
9        if (!RpgAtsumaruApi.Initialized)
10        {
11            // プラグインの初期化
12            RpgAtsumaruApi.Initialize();
13        }
14    }
15}