I have both arcgis online and arcgis portal organization accounts. I did all steps to create web appbuilder developer edition according to documents like this one : https://developers.arcgis.com/web-appbuilder/guide/getstarted.htm
I enter correctly both my Arcgis Online Url and App id, that i created in same arcgis online acount - contents. But i still get this error:
Error
Invalid redirect_uri
Error: 400
There is also another problem. When I type my portal Url, System doesnt accept it. I can only use my arcgis online account.(This problem is resolved. When I go to website with mozilla it doesn't accept my portal url, but with chrome it works. )
I tried different methods. But i always get this error. I also removed signinginfo.json file in /server everytime I fail entering website.