Known Issues
From Koingo Software Wiki
SIML Crashes
If the program reports a crash from SIMBL when it attempts to launch, it is likely a plugin problem. One known buggy plugin from another developer is "xsetapplicationiconimage.bundle." Please remove this plugin, or any others that you feel may be causing problems from the directories below:
Macintosh HD/Library/Application Support/SIMBL Home/Library/Application Support/SIMBL
Lost Settings or Corrupt Databases
Preference or database files may become corrupt, and settings and data stored will become lost, in the rare occurrence of a disk error. On Mac OS, after a reboot, sometimes databases can be recovered by visiting the Recovered Files folder if it exists in the Trash.
