Excel links saved in iCloud do not open on iPhone or iPad

I created an excel spreadsheet with links to PDF documents also saved in my iCloud. I can open the links on my MAC but they will not open on my iPhone or iPad. I get an error that says The link address my be invalid, or you may not have permission to open it. The folder is a Shared Folder.

[Re-Titled by Moderator]

Original Title: links in excel to iCloud documents not working