我尝试了您的请求，但也收到了 500 错误.根据这个 link，500(内部错误)是一个响应代码，表示*** 在处理请求时遇到错误.您可以稍后重试该请求.

I tried your request and I also get the 500 error. According to this link, the 500 (Internal error) is a response code that indicates that *** experienced an error handling a request. You could retry the request at a later time.

我尝试了不同的频道 ID 并获得了成功的请求.这是我使用的请求.

I tried different channel id and get a successful request. Here is the request that I use.

https://www.googleapis.com/***/v3/playlists?part=snippet&channelId=UCnExqEQyG6WemMK9hpQcoeQ&key=YOUR_API_KEY

我不知道是频道有问题还是 *** 本身有问题.但是，如果您尝试不同的频道，它会起作用.

I don't know if the channel has the issue or the *** itself. But if you try different channel, it works.

所以我建议像错误所说的那样，稍后重试请求.因为就像你几天前说的那样有效.

So I suggest like the error says, retry the request at a later time. Because like you said it worked some days ago.

有关更多信息，您可以查看此线程.

For more information, you can check this thread.