[phenixbb] On refine automatically correct N/Q/H errors

Dear All, I am refining a crystal structure with Phenix refine. I have adopted automatically correct N/Q/H errors. During refinement for some residues it writes "both conformations clash, check manually". Will you please tell me what does it mean for "both conformations clash, please check manually",   and how to process it? I am looking forward to getting your reply. Cheers, Dialing