@vdemerstreize usually this happens because there is some extra output added to the excel file. A whitespace or an error message. Maybe your functions.php or a plugin has this extra output.
Can you share a broken file with me on [email protected]?
Thanks in advance.
Sent! Thanks, I’ll also check for that.
@vdemerstreize Thank you for sending the information.
The reason the file is not working, is because the server is registering a Deprecation message. While the deprecation should be fixed; it is not advisable to have these deprecation notices active on a production website.
To remedy this issue for now, please add the following code to either your functions.php or wp-config.php
error_reporting(error_reporting() & ~E_DEPRECATED);
This will keep the reporting as it, but exclude deprecation notices.
I’ll make sure we look into the deprecation notice on our end.
Hope this helps you out.