I see no way that selecting "no" could have any affect on your exisiting databases. (Selecting yes, just down loads a free updater that still has to be run after the download before any change is made to your application.)
Thus, I would suspect some other factor is to blame here. What do you see on these layouts when you enter layout mode? Is text on these layouts visible then?
Do you have a back up copy of the file that you can open? Does it show the same thing?
I wonder if a Theme has been accidentally applied to this file.
Thank you for your message.
PhilModJunk is correct. Ignoring the update would not have any affect on text displaying like this. Checking a backup or the theme for the layout seems like a good "first step" in tracking this down as well as physically checking to see how the text has been formatted using the Inspector.
And you mentioned you checked another file and it did the same thing - have you tried one of the starter solutions or another of your file(s) to see if the problem is truly across the board?
Even if you applied v2, and that is always a good idea, I can't imagine it would change your files and layouts like that.
It does look like a Theme got accidentally applied. Good catch. Thanks!