Message in Chinese (Simplified) (中文(简体))
此 WebSocket 实例已存在一个未完成的“<var>X</var>”调用。可以同时调用 ReceiveAsync 和 SendAsync，但最多同时允许对每个请求执行一项待完成的操作。
Unlocalized message
There is already one outstanding '<var>X</var>' call for this WebSocket instance. ReceiveAsync and SendAsync can be called simultaneously, but at most one outstanding operation for each of them is allowed at the same time.
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