Is it just the one file that is incompatible? Which Photoshop version are you using. What did you save the cloud document with iPad Photoshop or some desktop version of Photoshop. Perhaps the file has been corrupted. Adobe iPad apps automatically write cloud documents not local iPad files. In the Creative cloud Web interface you can use the three dot menu item Download to download the psdc to see if the file has been corrupted by inspecting the download. If it is perhaps a PSD recovery tool can fix the PSDC. I was able to download a psdc to my desktop and open the desktop file in photoshop.
Thank you for your reply. Yes, looks like they are corrupted as even after downloading from the cloud it is still impossible to open those and that is super frustrating as the version of PS is the latest one and these files were saved in the same version.
I don't trust PS cloud anymore and would never save anything over there without a local copy as you can lose hours of your valuable work.
What is the PSD recovery tool you have mentioned? I could not find anything official, only some 3rd party tools.