Black Screen AE

Just in case, you also update your graphic card driver.

Sorry you're having trouble.

If this was a format that After Effects could decompress, you'd see the pixel dimensions, color depth, and CODEC type in the poster preview.  Your clip that starts with the name "Call" is not showing these.

You need to transcode the MP4 to something that After Efects can decompress or epxort it again containing picture that After Effects can decompresss.  Unfortunately, it's not enough for it to just have .mp4 as a file extension.

Supported file formats | After Effects

https://helpx.adobe.com/after-effects/kb/supported-file-formats.html

If you don't already have a prefered utility for transcoding, try Shutter Encoder (donationware, https://www.shutterencoder.com/en/).

Hey Kataroni,

Sorry about the issue. Are you having this problem with a specific source file or all files? Could you let us know what the source of the video footage is? Also, please share your system specifications (OS, OS version, CPU, GPU, RAM).

Thanks,

Ishan