I have an issue that is not specific to v25. It's been happening since 23 but not game stopping. When I discover some techs, the screen that's supposed to show describing the tech, buildings/units enabled just pops up for a split second and disappears. The audio, if any, still plays.
I think this is a bug with the 'minimize AI turn times' or possibly he 'auto-end decisionless turns' options - are you using either (or both) of these? If you have a reproducible case (from a save game of the turn before the tech is discovered, so ending turn after loading the save discovers it) post it and I'll see what's going on.