Thx !

Thx Yaron_Koren for your reply, the query you gave has no results.

Do you have some tip for helping me to debug this ? Is there a file where I should look in and var_dump some vars to see why this button is hidden ?

Oops, shame on me ;)
But still no "Edit tab with form"...

Thx Yaron_Koren for your tip.
I've changed this to {{default_form::Fiche Idée}} and it says now that the default_form value contains not allowed caracters.
And still no "Edit with form" tab : is that linked to the error above ?

Hi Oetterer and thx for the reply.

It appears on this wiki :
https://wiki.labomedia.org/index.php/Accueil

Here is the wiki where, when you edit a page, you can see the console logs :
https://wiki.labomedia.org/index.php/Blender:Appliquer_une_rotation_et_appliquer_une_orientation