Can someone explain why this glitch is happening when I export the video?

[Krum5F9D]

can someone explain why this glitch is happening when I export the video? Sometimes I see in in the preview also but not most of the times. Is my computer being too weak? If yes can I make some changes in the settings to fix it?

[manal shanableh]

while is is appear in final exported mp4 file, it is not a preview issue.

check your motion,

[Rick Gerard]

You have asked me to work on your car without lifting the hood or even telling me what kind of car you have. 

Workflow details, screenshots embedded* showing the modified properties of the problem layers would help. Reveal modified properties by selecting the layer and pressing 'u' twice. 

* The "Drag & Drop here..." area is buggy and should not be used to share images. Please use the toolbar or just drag your images to the reply field.

[Krum5F9D]

Hi, sorry for not explaining the things better. So basically I have 100 layers arranged one after another. I animated 1 of them and for the rest I used "thisComp.layer(index-1).transform.scale.valueAtTime(time - 0.01)" as a scale expression. 

And for some reason some of the squares flicker throughout the video without any apparent reason.Thank you for trying to help!