I am not sure when the following issue started for me. Looking at my commits, I was using the SDK successfully the last time end of June. I think that was SDK version 3.1.7. I tried to install that again, but it requests current version even if I use the offline installer.
SailfishOS SDK 22.214.171.124
The SDK is not able to detect that the Build Engine VirtualBox VM has been started. Clicking on the icon to start the VM in the SDK starts the VM but than tells me that it could not have started it. But VirtualBox Manager tells me that it has been started and I can also connect to it via SSH.
I also tried to use the Docker Build Engine, but there I have another issue. (sb2d says it detected an buffer overflow and terminates.)