Files open on Apple devices & previously on Windows 10.
Mac mini, macOS 15.5
To explain more: I can use iCloud/Pages on my Windows11 laptop to edit my Pages documents, as I can on my Mac.
However, on my new HP Windows11, iCloud/Pages loads a file (recognizing the password) but immediately says there's a problem and closes the file. I cannot find the Windows11 setting that causes this (if the problem is a Windows11 setting).
You might want to also post on the windows iCloud forum in case someone there can help
iCloud on PC - Apple Community
Windows can't open .pages files, you need to export them to another format like pdf or Word first. Are you doing that?
Windows sees the Pages document as the Zip container it really is and will attempt to unzip it. Once that is done, the file is permanently damaged. See Tom Gewecke's comments.
Did you previously have LibreOffice installed on Microsoft Windows 10, as that can potentially import Pages documents? How successfully?
Can't open Pages file on PC Windows 11
