When i take screenshots on my Ps Vita (Ps Button + Start) they do not appear, or appear as black images, but this only seems to happen with games. Does anyone know how to fix it?
Some Vita games and all PSP and PSX/PS1 don't allow you to take screenshots. For Vita games, this is usually chosen by the Developer or Publisher for unknown reasons. For PSP and PSX/PS1 games, this is by design of the emulators used for those systems.
This limitation can be removed on Vita consoles via Homebrew with a plugin called pngshot. The plugin will not only remove the screenshot limitation but also remove any watermarks when applicable and store the images as PNG Files.
As an example, here is a screenshot of Hatsune Miku: Project Diva (the original PSP Game) taken directly from a PS Vita with pngshot: