HI…
I am trying to create a virtual machine
but I receive this error " Can not retrieve response" on the Virtual machine Page
I have also applied this " [HOWTO: Fix Virtual Machines: Cannot Retrieve Response in 25.04.2]
but whitout fix the problem
That bug should have been fixed in 25.04.2.1. 
I think your best bet is to file a bug report for this, buuuuut I think all the devs are tied up in the 25.10-RC1 that should be out sooooooon.
Virtualization will allegedly be enterprise ready in 25.10, so moving to the new release in a couple weeks will likely resolve this.
I updated to SCALE 25.04.2.4 recently and noticed the same rough edges with apps and virtualization. Docker containers behaved fine, but some of the Kubernetes-based apps needed reinstalling before they ran properly. VM performance was okay after tweaking resources, but GPU passthrough still feels hit-or-miss. Overall it’s stable, but upgrades always need a bit of cleanup afterward.