Does this happen when you click on another already opened worksheet, or when you go to open a new worksheet?
And this happens every time?
In order to see what is going on in the JVM during the hang we need a full thread dump. Here is a primer on how to get one...
There are a couple of ways to get a full thread dump for a Java application.
If the application was launched from a Cmd window (Windows) or terminal (Linux)
1. Ctrl-Break (Windows)
2. Ctrl-\ (Linux)
and the dump will display there. You may need to increase the window or terminal
buffer size if the dump is large to avoid the first part scrolling off-screen.
It is usually more convenient, regardless of how the application gets launched,
to use the Java jstack utility to get a dump. To use jstack just
1. Open a Cmd window (Windows) or terminal (Linux)
2. Verify the PATH environment variable references a JAVA_HOME
The bin directory of the JAVA_HOME will contain the jps and jstack utilities
3. Use the jps utility to list the process ids (PID) of all Java applications,
then look for the process id of "OracleIdeLauncher"
4. Use the jstack utility to list a full thread dump. For example...
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.121-b13 mixed mode):