Dear SolidWorkers

Currently I am working on some sort of impeller. I therefore created one vane/blade, which I would like to replicate in a circular patern. This is actually the same thing I build last week, just to get some practice. I first created a surface which I thickened (without error). During the application of the pattern the error occurs without any explanation! Last time I did the build it did not occur Can anobody tell/guess what the problem is? Vanes will not intersect/collide in this setting but I also tried it with an axle already drawn.