white screen, how to debug?

While trying to get my feet wet in React and Wasp I now face a white screen after wasp start...
The browsers states: "You need to enable JavaScript to run this app." although javascript is enabled.

I found wasp clean acts like turning it of and on, so tried that.
After wasp start again I now have the 'wasp/client/operations" missing
Error Cannot find module 'wasp/server' or its corresponding type declarations.

Tried npm install without success...

How do I debug this? No errors are shown in wasp start

Any ideas