Is there a way to downgrade Visionaire, or are older versions available somewhere?

As it is currently not possible to create dialogues with the broken ‘dialogue area’ function and we are currently in the middle of a project (it's a bit of a nightmare, we have prepared so much for the whole thing with Visionaire and now there are no dialogues), I was wondering if it is possible to simply use a non-defective version of Visionaire?