Without knowing anything about the design or even the target device, it's not really possible to diagnose this. Can you provide more details or post the project?
You can also expand the error message to see exactly what the conflict is.
Hi @PKhan8 ,
Check clk_50 pin assignments.
Clock pin should be AF14/AA16/Y26/K14.
After changing the clock pin, I can run fitter successfully.
Let me know if this has helped resolve the issue you are facing or if you need any further assistance.