When breaking a door in PC-Realms, only the top half broke, then shortly after the Realms world crashed. Connection error listed in the log and no crash report. Internet access was not interrupted on the computer. Was able to download the world but cannot connect to the world in Realms. Opening locally had no issues (although the latest downloaded world was before the attempt to break the door). Attempting to restore Realm from latest backup continues for more than 15 minutes on a relatively new world (started less than 24 hours ago). Uploading the world that I downloaded when it crashed worked however, and I was able to continue playing.

Later, the same issue occurred but was not related to the door.

Log:
[17:50:16] [Client thread/INFO]: [CHAT] JustPlainSilly is now sleeping
[17:52:50] [Realms-connect-task/ERROR]: Couldn't connect to world
io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information: ec2-34-202-234-9.compute-1.amazonaws.com/34.202.234.9:26945
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) ~[?:1.8.0_25]
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:716) ~[?:1.8.0_25]
at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:352) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:340) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:612) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:559) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:476) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:438) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) ~[netty-all-4.1.9.Final.jar:4.1.9.Final]
at java.lang.Thread.run(Thread.java:745) ~[?:1.8.0_25]
Caused by: java.net.ConnectException: Connection timed out: no further information
... 10 more