XlsFile.OptionsForceUseCheckCompatibility Property
When the option ExcelFile.OptionsCheckCompatibility is true, Excel will refuse to austosave the file. To avoid a confusing situation where Excel refuses to autosave the file and shows a vague warning about an "older file format", ExcelFile.OptionsCheckCompatibility is ignored by FlexCel.
In order to force FlexCel to save ExcelFile.OptionsCheckCompatibility to the file (thus disabling the "Autosave" function) you need to set this property to true besides ExcelFile.OptionsCheckCompatibility.
Syntax
Namespace: FlexCel.XlsAdapter
public override Boolean OptionsForceUseCheckCompatibility { get; set; }