Uninstall "SIMBL" or "EasySIMBL" as follows. Back up all data before making any changes.
Triple-click anywhere in the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination command-C:
/Library
In the Finder, select
Go ▹ Go to Folder...
from the menu bar, paste into the box that opens by pressing command-V, then press return. A folder will open. From that folder, delete the items listed below (some may be absent.) You may be prompted for your administrator login password.
Application Support/SIMBL
InputManagers/SIMBL
LaunchAgents/net.culater.SIMBL.Agent.plist
LaunchAgents/net.infinite-labs.SIMBLEnablerForSandboxedApps.plist
ScriptingAdditions/EasySIMBL.osax
ScriptingAdditions/SIMBL.osax
Log out and log back in. There may also be an item named "EasySIMBL" in the Applications folder. Delete it, if so.
Make sure you never reinstall any variant of SIMBL. It’s likely to come bundled with another third-party system modfication that depends on it. If you want trouble-free computing, avoid software that makes miraculous changes to other software, especially built-in applications. The only real exception to that rule is Safari extensions, which are mostly safe, and are easy to get rid of when they don’t work. SIMBL and its dependents are not Safari extensions.