Opacity and feather doesn't work at mask currently I have the problem that I cant change the opacity of a mask.
It's just on (1-100%) or off (0%).
I noticed that the feathering doesn't work too.

Here is a example picture.



There are two masks, one with less opacity than the other, but they are still appear to be the same.

I tried different things but nothing worked and I can't find anything about this in at the internet.
Is it maybe because of the effects?

How can I change the opacity of the masks respectively the feather?
Normally effects are applied before masks, but some aren't. For these effects it means that you need to precompose the layer with the effect applied, and then apply the mask to the precomp. I don't know why, it's pretty certainly a bug, but Colorama is one of those effects. 

Turn off Colorama and your masks should start behaving normally. So what you need to do is pre-comp the layer with the effects on it, but not the masks (just select the masks and ctrl/⌘-x to cut, then precomp the layer choosing "Move all the attributes into the new composition", then paste the masks back).