Fix for "localized string not found" issue
Normally the problem is very specific, within the WebKit.framework. The System>Library>Frameworks>WebKit.framework>Versions>A>Resources folder should have the folder English.lproj, but it's probably missing. If the English.lproj folder is present, then the Localizable.strings file within it is missing.
Many people have mentioned the solution of downloading Safari and reinstalling after trashing the WebKit.framework. While this solution works, it's overkill and also require more updating. This is because the downloadable version of Safari isn't the current version, but rather requires the Combo Update to be re-run in order to re-update the entire Safari. Thus you'd need to Restart and wait for the whole Optimization process, a waste of time and effort.
The easier solution is to download Safari and then open the Safari.pkg package with Pacifist and navigate within Pacifist to whatever folder or file you're missing (hopefully only the English.lproj folder) and then highlight it and hit "Install" using Pacifist. If you're only missing the English.lproj folder you don't even need to quit Safari or Restart or anything, the problem will be fixed as soon as Pacifist installs the folder containing the "Localizable.strings" file.