[FIX] Gateways: Add error handling messages (RT-2654)
Merge pull request #1827 from yongsoo/fix/error

[FIX] Gateways: Add error handling messages (RT-2654)
[TASK] Main UI: Loading spinner (RT-2634)
Merge pull request #1829 from Mesrop/develop-13-11

[TASK] Main UI: Loading spinner (RT-2634)