View document

"만약 오스 데비안 유저시라면 꼭 어드민에게 말해주세요! If you were a 'osu! Debian user', please tell admin!!"

Installing the certificate manually

If you’re having troubles connecting to Redstar or the switcher doesn’t install the certificate properly, you can try installing it manually.


  • First, download the certificate by clicking here
  • Then, open certificate.cer
  • Click Install certificate…
  • Click Next
  • Select Place all certificates in the following store (second option), then click Browse…
  • A new window will pop up, select Trusted root certification authorities and click Ok
  • Click Next
  • Click Finish

How to test the certificate

Once you’ve installed the certificate, you can test whether it was successfully installed by following these steps:

  • Open the server switcher and click on Inspect.
  • Wait a few seconds and all the labels in the “Server connection” section, on the right, should become green and report “OK” (like this). If so, you should be able to connect to Redstar.
  • If you get CERT ERROR, the certificate has not been installed successfully. Follow the instructions below.
  • If you get ”…”, you’re not connected to Redstar. Close the inspect window, click on Switch to Redstar and try again.

If everything else fails…

…you can try to remove all existing Redstar certificates and install the certificate again. Follow these steps:

  • Press Win+R
  • Type mmc certmgr.msc in the run box and press enter to open the Certificate Manager
  • Select Trusted root certification authorities on the left
  • Select Certificates on the right
  • You should see some Redstar and some * entries in the list. Select them, right click and click on Delete
  • Select all the positive options (Ok/Yes etc)
  • Restart the switcher, click on Inspect, then choose Install certificate, then Yes
  • Click on Test redstar connection and you should see “OK” for every domains If the inspect dialog is fine but you still can’t connect to redstar from the game client, try running osu! as administrator.