I've had this problem for so long, I made a gif of it because I did so many posts about this subject trying everything.

Solution

Even with the solution presented in the comments (tags) I still could not finish the process of publishing. In the end the maker of dtube suggested to relog and that helped. Maybe, through relogging, we aregoing along with something that has been updated on the site and it's only refreshed when logging out and back in.

since then I had no probs