UE4 strange graphic issues

I need your help. I have some issues with my exported project. This project (once i have exported to a exe file) works only on a very powerfull pc. So i decided to reduce texture’s size of all meshes. Now once I have all successfull done, before making a test on other pc, I export the project on my pc and I see a strange problem in video screen. When i rotate the camera I see like a screen flickers witch I have never seen before. Flickers starts from bottom to top of my screen and the effect is very annoing.
Someone who can help me?
My best regards.

Can you upload a video of that?

Sorry I tried to capture the scene or a screen inside my game with a desktop recorder but it don’t works. There’s a way for recording in UE4 ??

This is very strange. I have captured the game scene with fraps but when I open the avi file, the flickers are not visible. It seems a continuos textures refreshing from bottom to top of the screen.

Sounds like Vsync is off, which can cause screen tearing. In a standalone game, type the console command “r.vsync 1” to see if that helps. You can set this in some .ini files to work on startup if you want. I used to have this issue constantly but haven’t seen it in a while. Assumed it was on by default.