Many thanks Cindy for your help. Alas I'm still getting problems, although the situation has improved somewhat.
In fact I don't think that any updates took place. I was able to get the list of updates, to connect the tablet and adapter (once I understood you had to shut the camera down) and the firmware was writen and verified successfully. But I did never get a feedback that the installation had successfully ended. The last time I waited for more than an hour and the confirmation never appeared. (The picture below show the last line of the feedbacks received). I will send it to the address you gave above in this thread.
Things however have improved a little : for a while I was no more able to connect the 45mm. So I couldn't even set the aperture to F90 because I didn't see any F value. Now I have determined that trying to mount the 90mm throws the adapter out of function. I tried several tricks to get it working again : mounting the lenses on A7r with either adapter (they work), mounting the older TGA1-B on the A7rII and the different lenses; they work if you change the AF system to contrast detect, although slowly, like on the A7r. Since the 45mm is working again, I tried to update the firmware another time, but the process still hooks after the installing begin. I waited a full hour without success. The last line I got isn't the confirmation of a successful installation, or is it ?