I am a chinese, my English is poor, Excuse me!

We use a Waters 1525 Breeze system, It have a RI and UV detection, When I process data, I open a method, for Example named A, modified and save, then I open other method, named B, modified and save too, OK,I open method A, I open method B, thus repeat this process, then after few times, error happen!, notice me, I will open the method A or B, is not exist! if I have been transferred method A and B to other project named P before this error happen, then I transferred method A and B from project P to first project , system notice me ,method A or B have been existted in the first project ,you need to overwrite yes or no, I choice no!, turn to first project, method A or B appear from disappear, but calibration curve is lost for relation method A or B!