VS 17社区版是免费的。你只需要用你的微软账户登录，一切就会恢复正常。

对我来说，问题实际上是我把机器弄坏了。配置和看起来像VS不能有一个连接 我在machine.config中添加了以下代码行

<!--
<system.net>
 <defaultProxy>
  <proxy autoDetect="false" bypassonlocal="false" proxyaddress="http://127.0.0.1:8888" usesystemdefault="false" />
 </defaultProxy>
</system.net>
<!--
-->

将前一节替换为:

<!--
<system.net>
 <defaultProxy>
  <proxy autoDetect="false" bypassonlocal="false" proxyaddress="http://127.0.0.1:8888" usesystemdefault="false" />
 </defaultProxy>
</system.net>
-->

VS开始工作。

不，社区版是免费的，所以只需登录并消除警告。欲了解更多详情，请查看以下链接。 https://visualstudio.microsoft.com/vs/support/community-edition-expired-buy-license/

VS 17社区版是免费的。你只需要用你的微软账户登录，一切就会恢复正常。

为了绕过“30天内必须在线登录”，登录一次微软帐户，你会得到%LocalAppData%\Microsoft\VSCommon\OnlineLicensing文件夹，你可以复制到离线电脑。

I had this problem. Signing in or pressing the "Check for an updated license" link did not work for me. My solution was to restart Visual Studio, try again (sign in and check for license). Restart Visual Studio, try again. I had to do this several times and then it worked! (I also tried pressing the "File" menu that is available for a short period of time before the annoying request window appears again.) Maybe you just don't get connected to the server or the server itself doesn't update its database fast enough.