Every time I say I want to save or quit or whatever, what should come up as yes or no just comes up as a white box. Nothing in it at all. I figured out that I can type y for yes, but that's about it. Is there any way to fix this? For reference, I'm on Windows 10 64 bit.

Check my post in another topic about this:
https://www.gog.com/forum/the_longest_journeydreamfall_series/cant_see_save_and_exit_options/post4

I saved the link and changed the png to a zip. I try opening the install and uninstall things, but all that happens is a window appears and disappears both in half a second. Do I need to move the contents of the file into The Longest Journey somewhere? Because that would explain a lot.

That is all the is supposed to happen. The files can be anywhere as long as they are all in the same directory.
Have you tried in the game if it actually works?

After installation you should also see a new entry "The Longest Journey Compatibility Fix" in Control Panel / Programs and Features (where you usually go to uninstall programs). If it's not there, then maybe the install didn't run correctly.

You can also try installing it manually as follows:
1. Open an elevated command prompt (click on the Start button, type "cmd" and press ctrl+shift+enter).
2. Type the following command:
sdbinst "D:\Downloads\tljfix.sdb"
(Of course the "D:\Downloads\tljfix.sdb" part is just an example, replace it with the actual path where the tljfix.sdb file is located on your system).

SOLVED! The white box is now a blue box with an option asking if I want to say Yes or No. Thank you narzoul. I'm also having some problems with a screensaver that doesn't quite work properly, but that can wait for another day.