It’s very uncomfortable to be a guinea pig… Chaos is playing games with its paying users… Where are the materials ?! They disappeared after updating to the latest release.
Do we have to harvest the entire library before the next update? 
Hello @cedric_vaucher ,
I regret to hear that you experience issues with the Cosmos Browser.
Can you please open your browser, go to http://localhost:30305/ and let me know if the materials are visible there? Thank you.
Hey @cedric_vaucher ,
We’re glad that restarting C4D solved the problem. I’ll try to explain what happened IMO. Cosmos Browser is standalone app and is shared between different host applications (C4D, Sketchup, etc.). Every host app connects to Cosmos Browser on start. Not every integration supports materials though (well, at this moment I think that every one that supports Cosmos supports also materials now), or in other words – materials are feature and while registering to Cosmos, the host app must tell Cosmos that it supports materials, so Cosmos UI can show them. Most probably for one reason or another, your C4D lost connection with Cosmos, and the UI hid the materials.
Features (like Materials) are not visible also on localhost:30305 and that’s expected ( @aleksandar.kasabov )
And then it stopped working again… Cosmos could not reach the server… had to download the installer to reinstall (the initial update mentioned above was done in-app).