Losing data while deserializing a DataSet?

Question

.NET

When serializing a DataSet object in binary or xml format, all the data is in the files themselves. When deserializing, in both cases, data is lost. Those. the same Rows.Count returns 0. Initially, the data was definitely there, I repeat once again that this data is saved in both the binary and xml files. By the way WriteXml and ReadXml work fine.
UPD1: tables with their columns remain. lines disappear.