Sorry for the late reply.
First, its important that you have the correct doc_generic_invoice_odt.modules.php file in your htdocs\includes\modules\facture\doc directory. Mine was corrupted so I did a fresh install of dolibarr somewhere else and copied the correct one from there. And then the generation started working.
The second problem I had was with the tags I was using in the ODT files.
Sometimes when you are typing in a tag, if you hit backspace or do anything else, the tag is broken because MSword or some other word processor puts invisible information between the letters which breaks the tag and renders it unusable.
Thirdly, there is a problem that I have yet to solve. Sometimes after I make a few changes to the ODT file I start getting errors upon hitting “generate”. For example, sometimes just moving a column in msword leads to an error in dolibarr. So my advice is, just start with a blank ODT and see if it works, and then save and make copies as you progress.
Hope that helps, good luck!
Deniz
