I was not able to take hide in plain sight feat at level 11. It would just reset my level up. I had to mess with leto to get that feat 
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Just telling you cause it was a bit annoying bug.
I have played ultimate ranger builds several times and always been able to take hide in plain sight, though it is possible that changes in recent versions could have caused a problem.
If I might suggest a different possibility, though, I have noticed that ultimate ranger is tricky if you aren't thinking about what you are doing very carefully on level up. That's because you can select anything an ultimate ranger could take at any level, regardless of what you are supposed to get at that level. In other words, you could accidentally select favored enemy when it isn't the right level, or (in the case of level 11), two special abilities when you are supposed to be taking one special ability and one bonus feat. (I used to make that kind of mistake all the time!) That situation will cause you to re-level. The manual makes the distinction clear, so when I play ultimate ranger, I always have a copy of the manual page close at hand, just in case.
