Adding .wav soundtrack messes up whole After Effects project

I added .wav file on top of my timeline and previewed it and it worked just fine. When i exported it via Media Encoder the background was kind of flashy. Then i deleted the .wav file and exported again and the background was still flashy and all kind of colours and mirrorpictures appearing in the background. What happened? How can i fix that? In timeline it looks normal, but mp4 file had all those mistakes in it.

First picture in timeline. You can see there is no mistakes. Second picture in Media Encoder, a lot of mistakes.