404. That’s an error.
The requested URL /add?source=atgs&feedurl=https://rongbay.com/rss/Dong-Nai/c278_Cho-Sim.rss was not found on this server. That’s all we know.
/add?source=atgs&feedurl=https://rongbay.com/rss/Dong-Nai/c278_Cho-Sim.rss