I have checked windows authentication in IIS
When you enable windows authentication, please make sure you have disabled anonymous authentication.
the WCF shows 401-"No permission to view the directories" error
edited permissions for all the folders by giving full access to the users
Usually this error is because iis does not have permission to access directories, but you have tried giving the user full access to all folders, please double-check that you have given
IIS_IUSRS full access to the site folder.
If it still doesn't work, please enable failed request tracing and post the error log here, it will provide the key error and warning.
This link provide the method to enable failed request tracing to capture the detailed error: troubleshooting-failed-requests-using-tracing-in-iis.
If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.