I've recently modified a report template and tried to upload it as a new report but I keep hitting the error message "The report template must be saved using Microsoft Excel".
The template is definitely in .xlsx format (I've saved using both MS Excel online and also in Libre Office -> Save as .xlsx) so I'm wondering if there is some way of getting further information into the problem with my template e.g. can you point me at the validator you are using?
I've previously has no problems modifying templates and uploading like this so any help would be gratefully received.
Many thanks