I've been pulling my hair out trying to get the PC Suite to connect to my ML629. Tried on different PCs, tried Windows 10 and 11. Just that error message at the top of the screen which didn't really help.
Anyway I have managed to get it connected and it is really simple. Basically just run up the PC Suite software without the ML629 connected and get rid of any messages at the top of the screen. Then hold down the left arrow button on the ML629 while you plug the USB connection in (you really need 3 hands for that). Within a couple of seconds it connects and asks you to login. After that I could see the updates which were available. I downloaded a couple although I'm unlikely to use them. The updates did work fine though.
I hope that helps anyone else that's struggling with this.