the exported video is different from the prview.

[YUVA30211274pci1]

This video of mine has been having many problems, but this one i dont know what to do like the preview is all good and normal but the actual exported video is having problems, i tried exporting it normally in after effects and tried exporting it in adobe media encoder but nothing is working. I have provided the attachment of both videos of preview and exported one, if anyone knows how to solve it please help.

[Warren Heaton]

It looks like your source MP4 footage is not holding up.

Try transcoding the MP4 clips to ProRes 422 LT outside of After Effects with Shutter Encoder (donation-ware) and replace the MP4 source with the resulting MOV files by selecting the MP4 in the Project panel and choosing File > Replace Footage > File.

Then render to "Best Settings" for the Render Settings template and "High Quality" for the Output Module (or a modified version that uses ProRes 422 LT or ProRes 422 Proxy instead of ProRes 422).  

Assuming that looks better, use Media Encoder to encode the AE export to H264 at highest bitrate that where ever you are uploading the video to supports.

[Andrew Yoole]

What specific problems are you concerned about?