Error message:

The game crashed whilst mouseclicked event handler
Error: java.lang.NullPointerException: Cannot read field "g" because "☃" is null
Exit Code: -1

Crash report file attached.

Steps that led to the error:

• have expired realm with single world
• delete realm from client
• client goes back to realm selection list
• click configuration button on bottom of the window (same as the one used to enter own realm settings)

After relaunching client, realm is no longer there, and configuration option is not available.