Ignoring location assignments due to preservation at their previous fitter locations

Dear all,

When I use the logiclock in Quartus II to assign a design into a specific region (let's say region A), the warning is shown as:

Warning (171094): Ignoring location assignments for the following nodes because they are being preserved at their previous Fitter locations.

How to solve such warning and put the design into region A successfully? Thanks very much for your help on it.

Best,