Today I discovered that DOff missions no longer have success rates that depend on the skill level or speciality of the assigned DOff. Every missoin has an assigned success rate that does not change whether I assign a purple DOff or a white one. The failure rates have also increased radically for no apparent reason. It takes all the fun out of the DOff missions when nothing I do affects the chances of success. It would be kind of like having the Road to 2409 Mission come out the same whether you got the right answer or not. With the high failure rates and the lack of any way to affect the outcome, the DOff missions are nothing more than a game of Russian Roulette in disguise. Bummer!
If you would have just looked at the first page of this section of the forums you would see the other bug reports on this subject, as well as the Dev response saying they were aware of it and a fix would come soon.
I would suggest for now simply doing the low or no risks DOFF assignments until then.