Puntuado con 5 de 5 estrellas

R.I.P SmartTemplate!
SmartTemplate don't work properly after Thunderbird 12.*.* (script stop prompt and double Header) since much changes included in Thunderbird 13.
In SmartTemplate4 0.8.5.6 are this BUGS fixed, SmartTemplate4 work properly!
Upgrade needed?
Please switch to SmartTemplate4, you can use your settings and Templates from SmartTemplate, no further settings after upgrade needed!
https://addons.mozilla.org/thunderbird/addon/324497/

Puntuado con 5 de 5 estrellas

@ hanjo: you use Lightning that's the reason that Smart Template don't work well. Please deactivate Lightning and Smart Template will work well again!
More informations you can find on my AMO Page (see follow).
I have upload a new SmartTemplate (SmartTemplate4) for Thunderbird 4+ (i'ts exactly the same like Smart Template but an active development)!
You can find it here:
https://addons.mozilla.org/en-US/thunderbird/addon/smarttemplate4/
https://addons.mozilla.org/de/thunderbird/addon/smarttemplate4/