master server

so i see a server is name "Lex's SRB2Ware" on the "ms.srb2.org" and i think is a good server so i open my srb2 but i dont find it in srb2's master server if i change the masterserver link to https://ms.srb2.org/MS/0 it will crash idk why ,have someone to explain this?

One of my servers prints out this: Registering this server on the master server... HMS: connecting 'https://ds.ms.srb2.org/MS/0/rooms/33/register'... HMS: connecting 'https://ds.ms.srb2.org/MS/0/rooms/33/register'... ERROR: There was a problem contacting the master server... From...