Blackbox crashes the JVM on Linux if you try to dump a specific entity from its menu

Knowing me, it's probably something stupid I did which caused it to do that.
```none
X Error of failed request:  BadWindow (invalid Window parameter)
  Major opcode of failed request:  20 (X_GetProperty)
  Resource id in failed request:  0x620007c
  Serial number of failed request:  47878
  Current serial number in output stream:  47878
```