1. Use a smaller tool to achieve the programmed radius.
or
2. Use a larger radius in the program.
or
3. Use a combination of both 1 and 2.
or
4. If caused by to short of a lead-in, increase the lead-in distance.
There are a few scenarios that you would get this error. As stated above, it could be caused by to short of a lead-in when applying the tool comp. It could also be caused by a bad choice of tool diameters, or to small of a fillet radius in the part program. If you could post your code, and tell us what cutter your using, we could get a better understanding of what's going on.