X marked Premiere sequence in After Effects

Hello,

I need some help please, I've been googling everywhere but no luck...

We're using Team Projects for the first time, two collaborators - editor is working in PP and graphics working in AE. All our assets are in the Creative Cloud, only audio files are stored on local editors machine and not shared, because only editor needs them. 

All was ok, but today when we opened the project in AE the PP sequence is disabled and we get a notification about media offline and media mapping. In PP everything is fine. We didn't move or delete any files.

We're wondering why is the sequence suddenly disabled in AE? 

Premiere version is 14.4.0