Ubuntu Gnome Facebook login error

Solution 1:

I just faced the same issue. The window is non-resizable and its size does not depend on the resolution.

While it is not possible to use control + scroll wheel or other usual key combinations to change the font size and make the login screen small enough to fit, you can use the tab key to select the "Okay" button located underneath the semi-transparent warning text and press enter to validate the form. You must do that again on the following confirmation page.

If you don't touch anything on the page, the "Ok" button is actually already selected, so you should only have to press enter twice.

Hope that solves your issue.