If you’re new to Ushahidi and gave problem in your setup as the example below:
Fatal error: Call to undefined method Locale::get_i18n() in /opt/lampp/htdocs/ushahidi/application/controllers/main.php on line 106
I had the same problem that i solved renaming the locale helper that produces the error. After renamed it you can simply change the lines where the locale helper is used.
I renamed locale.php by localeush.php and core class for localeush_Core
I also modified the following files in the specified lines.
Now all works fine for me.