apparently @microsoftuk is blocking access to windows 10 iso downloads ! why ?
and only allowing you to make an ISO locally with the windows media creation tool
but groovypost claim you can still get an ISO by downloading from linux instead of windows
opting in to @microsoftuk #windows insider builds s easy ! opting out is a bit harder
You can either opt out with the next production or publicly released build, or restore your device to its original operating system.