Efficy 11 ships with Export to Excel enhancements, as can be seen in the 11 release notes.
The export to Excel is completely renewed with version 11, there is a new engine behind it that allows to have a WYSIWYG export. R&D talks about an enhancement, because the new engine is feature rich compared to the old one.
For instance, with the usage of ExportColumns.txt you can layout the exported columns:
- Datatype formatting: currencies, numbers etc. Previous version was only exporting strings
- Alter the sheet name
- Set column dimensions, like width
I assume that your query hits the limits of the new component, in terms of row size. If you reduce the amount columns, I wondering if you manage to make it work again.
If customizations don't work, you are doing it wrong :-)
Try to be more specific if you want assistance on that by making a new post with details of the customization.