26.1.0: "Unrecognized request" error at launch (VMs run)

Since updating both of my MacBook Pros to Parallels Desktop 26.1.0 (build 57287), I get this dialog every time the app starts:
"Unrecognized request. The remote server does not support the requested operation."
Dismissing it lets my Windows 11 VMs run normally. I've already signed out of Account & License, quit, relaunched, and signed back in--no change. No VPN/proxy involved. The issue reproduces 100% on two separate Macs, so it looks like a backend/handshake problem rather than something local.

Could Parallels please confirm and advise on a fix or workaround?

Host macOS: [version/build]: 15.7 Sequoia on both

Edition: [Standard/Pro/Business]. Pro on both

 

Sharing is broken between MacOS host and Windows 11 VM on both computers. This release is a disaster! Rolling back.