Azure Data Lake File Input/Output

For Azure AD, it should typically be :     login.microsoftonline.com/ AND Ensure it starts with ‘https://’

Endpoint URL might not be in the correct format.

For Azure Data Lake Gen1 : 

https://.azuredatalakestore.net

For Gen2 (Blob) :
https://.dfs.core.windows.net

AND : 

Make sure you select Service-to-Service and fill all fields.

If the window still goes blank, try:

– Updating Alteryx Designer to the latest version (your screenshot shows a newer version is available).
– Running Alteryx as Administrator.
– Checking if any proxy/firewall is blocking the OAuth call.