Hello, I have lvl 50 FED character and recently started playing with now level 31 KDF officer, but I'm stuck in this mission: http://www.stowiki.org/Mission:_Destiny I reach I.K.S Bath, but there is no Breen attack group, I tried it twice, traveling up and down, also to the planet and back and still no luck What am I doing wrong?

no idea.. try dropping and retaking the mission.. read the mission text carefully as you go through. theres a number of bugs in missions KDF side unfortunatly.. I'm thinking theres something you forgot to do.. but I don't recall what it is.

Same thing happened to me. It glitches sometimes I guess without a reason. I resolved it by hitting the "transwarp to Qo'noS" button, and when I was back in Qo'noS orbit the option to continue the mission and warp to I.K.S. Bath.
The second time I arrived there were Breen ships waiting to wellcome me back.
Try that, it might work for you as well.