nunjucks - fastify と nunjucks を使用すると HPE_INVALID_METHOD エラーが発生する原因は何ですか?

Question

POVを除くサーバー上のすべてのプラグインを無効にしました。

fastify.register(require('point-of-view'), {
  engine: {
    nunjucks: require('nunjucks')
  },
  templates: 'server/views',
  includeViewExtension: true
})

ハンドラーがビュー関数を呼び出しています。

reply.view('/v1/main', {
  nonce: nanoid(1),
  token: nanoid(1)
})

完全なエラー メッセージは次のとおりです。

{"level":50,"time":1547208496144,"msg":"client error","pid":16013,"hostname":"jer-ryzentwo","err":{"type":"Error","message":"Parse Error","stack":"Error: Parse Error","bytesParsed":0,"code":"HPE_INVALID_METHOD","rawPacket":{"type":"Buffer","data":[22,3,1,2,0,1,0,1,105,3,3,167,247,206,59,236,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}},"v":1}

{"level":50,"time":1547208496145,"msg":"client error","pid":16013,"hostname":"jer-ryzentwo","err":{"type":"Error","message":"Parse Error","stack":"Error: Parse Error","bytesParsed":0,"code":"HPE_INVALID_METHOD","rawPacket":{"type":"Buffer","data":[10,0,1,0,2,2,20]}},"v":1}

この問題の原因を特定できません。HPE_INVALID_METHOD エラーが生成される原因と理由は何ですか?