After Effects Transparent Export, Weird Fragments?

[Johann307018349k56]

Hey,

whenever I export my transparent clip in media encoder using RGB + Alpha (GoPro Quicktime), those weird rainbow fragments appear on my video...

Anyone know how to fix this?

Tried keying it, using a different render encoder, fixing transparency in Photoshop, it all didn't help...

Attached a Video and an Image.

Please help me 😉

[Rick Gerard]

I am guessing that your Project is set to 8-bit, and so is the export, and that your alpha is not completely clean, and that you have not set the Alpha Chanel to Straight. 

I would set the project to 16Bit, make sure that the alpha is clean, and use the High Quality With Alpha preset or choose ProRez 444 and export at trillions of colors and straight alpha. If the key is clean, that should solve the problem. 

[Johann307018349k56]

Didnt work either...