Atm i've done 7 of those quest, take 2h30 min and cost 3.5k credit, atm 4 have failed and i just started my 8th one... What's wrong whit this, is it really intended or i'm just very unlucky ?

 

And yes i'm 400/400 and doing those whit Vette, which have a +5 to crit chance whit treasure hunting

i did 2 and both went fine. whats your character's friendship bar at? higher is obviously better. i dont run missions with the ship droid anymore because he seems to fail 20-30% of the missions no matter what.

I would guess that there is always a percent chance of the mission failing.

 

With my crew skills not being as high as yours though, I have had a 100% success rate on the mission discoveries. Some of the things I do is first making sure that I send the crew member on the mission that gains a bonus in that "field". From doing so, I have had very successful yields. 60+ items return (totaled up from the different stacks) from each one.

 

It maybe just a bad luck on the roll of the mission itself. 50% though seems to be very high IMO. Only thing I can think of is the possibility of not sending the companions that have a bonus for said missions.