When exporting to Excel, if the spreadsheet has any validation (using range.validation(string here)) then the Export fails to open in Excel 365. Error message is below:
<?xml version="1.0" encoding="UTF-8"
<summary>Errors were detected in file
-<removedFeatures summary="Following is a list of
<removedFeature>Removed Feature: Data validatin from
Currently we get around this, by removing all the range.validation before we export and then add it back afterwards. However this is incredibly slow (over 15 seconds, when the spreadsheet has only 3 rows populated).