Your question is extremely vague. There are a number of problems that you could be encountering. Did you start with the XM105 PCB design files and then modify them? I think it is typically lower risk to take an existing board and mofidy it then to start from nothing.
You will need to do a pin by pin comparison. You should also compare your use of the power rails with the specification at https://www.vita.com/fmc.
You could check with your local Avnet FAE to see if they would be willing to take a look at your design.