LeanLord I'm still not sure why this isn't translating for you, as the corrected strings are in the language file.
"Unable to create a ticket" and "Correct any errors...." are in open.php (root directory of your osTicket installation) on lines 54 and 55
"Enter a valid email address" is in /include/class.forms.php on line 1449.
I'd really suggest you try to work out why the translation strings aren't being applied, and ensure you have the latest available language pack installed. If you're modifying these strings in the source files manually, you'll have to do it each time you upgrade. (and not upgrading will mean nobody can help with any future problems!)
