Hi I'm new to the community and to Confluence in general, so please let me know if there is another resource or place I can go to. I need to upload an Excel file to a page and have that file be editable from that page. To display the file and have the ability to edit it more or less from the page, I found the Excel macro and downloaded the Atlassian Companion app after reading this article: https://confluence.atlassian.com/conf615/edit-files-967337829.html
However, when I click the edit button, I get the following error message pictured:

I have tried removing the attachment and reuploading as xls and then re-downloading, but got a different error message indicating an HTML issue, but I'm afraid I'm not literate enough in this kind of issue to know how to fix it. Any tips?