I've just upgraded my Billings app. to version 3.
But when I startet the app for the first time it comes with the "Billings upgrade assistant" saying "Progress" converting templates.
- It has been hanging at this screen for hours now :0(

What do I do?

I've tried to force quit and start billings again, but it hangs at the same screen.

I really need to create some invoices what can I do to get the application running again?

Remove your custom templates from Home -> Library -> Billings -> Templates

Once 3 starts, you can convert the required templates using Menu -> Design -> Conversion.

If the problems persists, email the template in question to support [at] marketcircle

Thx.

Correction here. Your templates are in Home > Library > Application Support > Billings > Templates.

Also, make sure you are using Billings 3.0.1, which should prevent most template converting problems.