Months ago I created a PPTP server on 2 mikrotik routers at 2 different locations. One of the locations quit working a couple weeks ago. No settings have recently been changed on the router. It works from an Ubuntu client but 3 different windows 10 clients from various internet connections can't connect. No errors in the windows log just a warning on TCP not establishing a connection 829 although the mikrotik log shows that a connection was briefly established. The same windows clients are still able to connect to the other PPTP server at the other branch. I'd appreciate any ideas.

I am having the same issue on a 6.40.6 RB2011. Previously working Windows 10 VPN, stopped working. I have not changed ROS version, but client Windows version has probably updated.

I suspect that there's been a deprecated cipher causing a problem.