Hey there, I'm very sorry to read that you have not been able to load up Rainbow Six Siege recently! This is obviously not ideal and I would like to see if we can get this fixed so that way you can get back to playing and enjoying the game. Please try all of the steps below and then test your game again to see if it will start up for you.

- Ensure the game is installed on the same drive as both Steam and Ubisoft Connect
- Clear the cache in Steam
- Clear the cache in Ubisoft Connect[www.ubisoft.com]
- Complete our guide here[www.ubisoft.com]
- Run Microsoft's System File Checker tool[support.microsoft.com] to repair any missing or corrupted files
- Reinstall the supporting software[www.ubisoft.com] for the game

However, if you are still unable to play your game after those steps then I would encourage you to create a support case[www.ubisoft.com] with us and attach[www.ubisoft.com] your MSinfo[www.ubisoft.com] and DxDiag[www.ubisoft.com] files. Just make sure that you list all of the steps that you completed here on your case so that you do not receive a repeat of steps.