Suddenly the Meteor dev environment wont start anymore! HELP NEEDED

I have developed about twenty different Meteor apps. Suddenly this morning my development environment didn’t start at all. I’m using Windows 10.

I have removed the meteor installation and the .meteor folder from %AppData%. I have reinstalled meteor several times.

meteor create test works

meteor run does not work.

throw error;

I added --trace-uncaught to the end of meteor.bat file

now it says
Maximum call stack size exceeded
thrown at C:\Users\xxx\AppData\Local.meteor\packages\meteor-tool\1.10.2\\dev_bundle\lib\node_modules\meteor-promise\promise_server.js:7 at Processtickandrejections (internal/process/task_queues.js:79:11)

In the file promise_server.js at line 7 is
if (typeof Fiber === "function") {

I have reinstalled npm and node. Rebooted several times before and after reinstalling.

What could cause this or how to solve this problem? How to debug this?

Thank you!