the exported video turns grey

[NADINE CHRIST38226638kyux]

Hey there, i am trying to render my after effects compositions and after i exported them they always turn out with a grey overlay which covers the footage and moves. Does someone know whats the issue is? 

[ToolfarmJP]

You check your alpha channels or masks of the footages on the timeline before the rendering. You turn them off or remove them if they are unnecessary.