Hi,
Ensure that you have the correct ServerPool option in your Diablo III Game Settings:
From the Battle.Net launcher,
- Click on the blue Battle.Net logo in the upper left corner and click on Settings;
- Select “Game Settings” in the left panel;
- In the right panel, click on “Diablo III” if it’s not already expanded
- Put a
for “Additional command line arguments” and
- Write
OnlineService.Matchmaking.ServerPool=Default
in the box under it.
Click Done to save the change and close the panel… and retry.
Best of luck in your games !