[Ifeffit] Athena open data project but not shown the curve

Hi all, I processed a series of data using IFEFFIT Athena, and saved it as a project. Later, when I opened the project in IFEFFIT Athena, the plot window did not show the curve. I tried to open the project in Demeter Athena, but popuped "Can't call method "datatype" on an undefined value". The data curve was also not shown. I want to know what happened to this? Are the data damaged? I am very thankful if this problem can be solved.