Not any overrides, just pure TB 1.0.3 Installation
You have to make changes into code of that module, if there are no mail templates to currently installed languages, always to use the English templates, so such things to not happen again.
[quote]
It basically means that if there are no translations available and English is not active, it will not send a mail to prevent it from crashing.
[/quote]
Next release should check if there are translated templates in /mails/xx, and if is empty to fall back to English.