If I click on OK, the same window appears again on top of it, even if I leave my finger on [enter], the window keeps coming back, so... Like the Mafia, there's no getting out!

The only solution left for me is to open Task Manager and kill RCC...
After that, it reconnects perfectly.
RCC: 2.06 (timeout set to 40 seconds, HM server is on the same subnet)
HM: 6.80
Thanks.