PyCharm 2020.1启动不了，报错信息如下
Internal error. Please refer to http://jb.gg/ide/critical-startup-errors
java.util.concurrent.CompletionException: java.net.BindException: Address already in use: bind
at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:314)
at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:319)
at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1702)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.net.BindException: Address already in use: bind
at java.base/sun.nio.ch.Net.bind0(Native Method)
at java.base/sun.nio.ch.Net.bind(Net.java:455)
at java.base/sun.nio.ch.Net.bind(Net.java:447)
at java.base/sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:227)
at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:134)
at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:550)
at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1334)
at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:506)
at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:491)
at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:973)
at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:248)
at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:356)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
... 1 more
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JRE 11.0.6+8-b765.25 amd64 by JetBrains s.r.o
D:\Program Files\JetBrains\PyCharm 2020.1\jbr
按照提示信息官方的指导，问题解决了：
按照提示信息给出的网址 Internal error. Please refer to http://jb.gg/ide/critical-startup-errors
寻找解决方法，操作如下：
管理员身份运行cmd
PS C:\WINDOWS\system32> cmd
Microsoft Windows [版本 10.0.19044.1586]
(c) Microsoft Corporation。保留所有权利。
C:\WINDOWS\system32>netsh int ipv4 set dynamicport tcp start=49152 num=16383
确定。
C:\WINDOWS\system32>netsh int ipv4 set dynamicport udp start=49152 num=16383
确定。
C:\WINDOWS\system32>net stop winnat
Windows NAT Driver 服务已成功停止。
C:\WINDOWS\system32>net start winnat
Windows NAT Driver 服务已经启动成功。
C:\WINDOWS\system32>
执行完以上四个命令，问题解决。
