Couldn't download rootfs list from the server.
I'm trying to use FEXRootFSFetcher but I'm getting this error:

```
Using default interface naming scheme 'v255'.
INFO <sommelier-scope-timer.cc:30> ~ScopeTimer: configure event loop: 0.00027375 seconds
INFO <sommelier-scope-timer.cc:30> ~ScopeTimer: drm device: 0.0185686 seconds
INFO <sommelier-scope-timer.cc:30> ~ScopeTimer: connect display: 1.7583e-05 seconds
INFO <sommelier-scope-timer.cc:30> ~ScopeTimer: client create: 1.3125e-05 seconds
INFO <sommelier-scope-timer.cc:30> ~ScopeTimer: display implementation: 4.708e-06 seconds
INFO <sommelier-scope-timer.cc:30> ~ScopeTimer: spawn xwayland: 0.000207125 seconds
Couldn't download rootfs list from the server. Try again in a minute or report on the fex-emu issue tracker.
"FEXRootFSFetcher" process exited with status code: 255
FATAL <sommelier.cc:2960> sl_handle_x_connection_event: got error or hangup (mask 5) on X connection, exiting
```