Can’t run Ubuntu 26.04 in WSL2 on Win11 after install

I have WSL2 installed on Windows 11, it’s been installed and working for several years already, with the previous 2 LTS versions of Ubuntu installed and working fine. Today I opened Powershell and installed the newest LTS with

wsl –install -d Ubuntu-26.04

It downloads and installs successfully. But when I try to run it I just get the message

Catastrophic failure
Error code: Wsl/Service/E_UNEXPECTED

Help appreciated