Thanks for the template file and details.
After an initial test, I observed the issue as you mentioned by using the following sample code with your template file. I found Excel file is corrupt due to data validation range after opening and resaving it via Aspose.Cells APIs. I used the following sample code to convert your SpreadsheetML file to XLSX file format:
Workbook wb = new Workbook("e:\\test2\\DataValidationReverseRange.xml");
I have logged a ticket with an id “CELLSNET-45570” for your issue. We will look into it soon.
Once we have an update on it, we will let you know here.