Just check for updates in MS store below … icon next to your profile picture.
But in your case the Darwin package isn’t installed at all, so it’s missing from the list and is probably the reason why that package isn’t installed (yet).
Are you signed in with MS account as added user account or through local administrator account? That 0x8000FFFF is really hard to troubleshoot.
Could you also post a screenshot of your MS store update history?
Also I’ve read somewhere they have some issues on releasing the latest build of AOE DE to MS store, so maybe installation of current version is on hold until new version is ready.
Release notes here:
I’m still on 27805 with the cross play release version.