Realtime API custom collaborative objects' models got wiped out over night

[Jimin Park]

As the question title says, our models got wiped out over night.

We set the collaborative strings again in our models and everything is working fine again. Of course we can't go back and re-initialize for all of our clients and this is causing a head-ache. Here is an example.

1. load the file

gapi.drive.realtime.load(fileId, onFileLoaded, null);

2. inside onFileLoad, we retrieve previous collaborative strings

var title = doc.getModel().getRoot().get('title');

Here all of sudden we are getting null assigned to the title since this morning.

Could anyone shine an insight on this issue?