When I try to enter 'yes' in the required field I get a error message that states that value is forbidden. The rollups doesn´t work in the excel document. I use Excel 2013 and I guess that could be the cause of the message.
You can remove the data validation by highlighting the column in Excel, browse to the Data menu and select Data Validation. From here you can remove the data validation to make the cell accept any values.
Thanks for the reply and the solution.
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