The multi ring buffer tool appears to be somewhat more limited than the buffer tool. There is no indication that it uses geodesic buffering like the Buffer tool and you seem to be using geographic coordinates and then trying to specify buffers in kilometers. I would suggest that you project your data to an appropriate projected coordinate system, and then try the tool. You need to make sure that your buffer size is appropriate for your new extent.
Alternately, you can use the Buffer tool to produce your buffers and intersect the results.
Since the Multiple Ring buffer tool is a Python script, you could get information on how this process of intersecting the buffers is done script-wise or get the syntax for use in the tool