This image here is about the error http://i.imgur.com/ywgpmR2.png

i alreday tried to update the OpenModsLib, but the problem persists

One of the mods needs OLD version of OpenModsLib. [0.7.1,0.8) means 0.7.1 or older, but not 0.8 and older (and no, we can't make more descriptive notation since a) it's FML thing and b) it's widely accepted notation for open ranges).

Update all mods to current version.

is there a way to know what mod is requiring an old version of the libary?

Should be somewhere in console/logs.

Thanks :)