Graphic issue in AoE2 de flickering and green screen

I installed Aoe2de a couple of days ago. First it worked fine. But then suddenly the fog and partly all of the screen turned into light green. When i lowered the graphics settings it turned normal again but after this insident it looks like the graphics where lovered overall. In particular there is white or black flickering on the edges of the borders of each unit. Is this normal for Aoe DE to have this flickeringing? I have tried all types of settings inside and outside of the game. The computer is pretty good but i bought it from a Company on second hand.
This is my system information;
Windows 10 Pro
Intel Core i5-4590 CPU 3.30 Ghz,4 cores
Nvidia GeForce GTX 1650 (4gb) (new)
8 gb ram
new aoc monitor with 144hz refr.
version of aoe2 de; 101.101.35209.0
theories sofar;

  • ram 8 gb is not enough?
  • Intel Core i5-4590 CPU 3.30 Ghz,4 cores is to old.
  • anything else? i have tried to reinstall the game on both my fast ssd and my slower harddisc without change.