Facing difficulty in using ArcGIS Web AppBuilder Developer Edition

[Abhi0829]

Hello Everyone, 

The user is using Web App Builder Developer edition for creating customized WebApp. Everything was working fine and all of a sudden the batch file stopped running where the it automatically picks machine name (Screenshot1): 

Abhi0829_0-1683523721654.png

It also did not work with FQDN and IP as well. But it did work if it was replaced with localhost (Screenshot2)

Abhi0829_1-1683523822207.png

But after clicking on Continue on the above screen, it gives the below error of Invalid redirect url.

Abhi0829_3-1683524000344.png

And when we try to log in from the top right corner of the above screen, it throws the below error:

Abhi0829_4-1683524103416.png

The thing to notice is: The Web Adaptor for the portal here used is: arcgisportal as you can see in the 3rd screenshot but then trying to login it changes the WebAdaptor name to arcgis and thus gives this error. 

Please Note: There are 5-6 client machines working with the same enterprise perfectly but this one particular machine started behaving abruptly. Any help will be highly appreciated. 

[BrianLeroux]

Here are some things i would try first.

1. See if user can log into portal directly? If not are permissions OK?
2. Clear browser cache.
3. Based on the 400 error maybe flushing the DNS will help. Type 'ipconfig /flushdns' in the Command Prompt, and press Enter.