A JavaScript error occurred in the main process

I'm running:

• Parity client version:
  according to the CLI: version Parity/v1.11.5-beta-0487c5b-20180629/x86_64-linux-gnu/rustc1.27.0
  according to snap store: v2.2.9
• Parity UI version: 0.3.5
• Operating system: Linux Ubuntu 18.04
• Installed via: snap
• Fully synchronized: yes
• Network: kovan
• I tried to restart both Parity UI and Parity Ethereum client: no / yes

This is what I get when starting parity-ui without fully synced:

Error: A JavaScript error occurred in the main process
Uncaught Exception:
Error: spawn /home/username/snap/parity-ui/38/.config/parity-ui/parity ENOENT
    at _errnoException (util.js:1024:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:190:19)
    at onErrorNT (internal/child_process.js:372:16)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)

This is what I get after sync and restart:

Parity Error: An error occured while fetching parity.
Please attach the following debugging info:
OS: linux
Arch: x64
Channel: beta
Error: getaddrinfo ENOTFOUND vanity-service.parity.io vanity-service.parity.io:443
Please also attach the contents of the following file:
/home/username/snap/parity-ui/38/.config/parity-ui/parity.log

Please quit the app and retry again. If the error message persists, please file an issue at https://github.com/parity-js/shell/issues.

parity.log is empty