Check for plugin updates failed and infinite loading of Plugin Catalog

[hamish211 0]

Hi! Can you help me for this issue?

Xpenology DSM 7.2, Emby version 4.9.3.0, fresh Emby reinstall, plugin catalog infinite loading.
TMDB/DNS issue was fixed (standart DNS-server doesn't provide me access for this resource).
Local request to "http://127.0.0.1:8096/Packages?TargetSystems=Server&IsAdult=false&PackageType=UserInstalled&api_key=null"
still hangs indefinitely.

Scheduled task "Check for plugin updates" stays running and during shutdown Emby logs: "Check for plugin updates: Timed out waiting for task to stop".

All ports are opened, firewall disabled.
The same problem was at version 4.8.11 (installed from Synology repositories).

embyserver.txt

[Luke 42266]

Hi, that's strange. are you using a vpn?

[hamish211 0]

No, my DSM doesn't, just router port forwarding. You think the problem is caused by some inaccessible resource? How to find out which definitely? 

I saw the same thread in russian community: https://emby.media/community/topic/145846-не-открывается-каталог-плагинов/
It seems to me, that there is the same problem, so I have to try with VPN to get inaccessible resource?