Azure website message "You do not have permission to view this directory or page.". What to do?

You do not have permission to view this directory or page.

That basically a hint that Azure encounter an error while running your web app. Since its in production, it does not show any useful error messages. For testing/debugging purposes you can turn on the Azure detailed messaging, and turn back off when its ready for production. To do so, you have to follow these two steps,

• Login to Azure > App Services (left side menu) > Your Web App > App Service logs (search box is at the top if you can't find it), then turn on Detailed Error Messages or turn on all of the logging options, up to you.
• Now add the following in your Web Config file,
• In your Web Config file add <customErrors mode="Off" /> BEFORE system.web closing tag, </system.web>. Similarly, add <httpErrors errorMode="Detailed"></httpErrors> BEFORE </system.webServer>. Finally, upload the Web Config to Azure and cross your fingers.

If you follow the steps correctly, that will show the error messages in detail and hopefully from there you will figure out what went wrong. Good Luck!

• The fist thing you should do is actually go and check the folders if your war got unpacked inside the webapps folder. for that if your web url is "xyz.azurewebsites.net" then try to open xyz.scm.azurewebsites.net. This should redirect you to KUDU interface where you can see few tabs. From those tabs select Debug Console and then select CMD from the drop down. This should give you a folder structure.Now Go to site->wwwroot->webapps . There check if your war got unpacked.
• If not then try restarting the web app and see id this does the trick. If while creating your app service plan you have selected the Standard pricing tier, change it to premium
• Last but not the list you can enable logging for you app. Then go to Monitoring-> Diagnostics logs . Turn those setting on. Then select Log streaming(Just below Diagnostics logs).

Hope this help.

From my experience, if your login user ID under Azure Active Directory (AAD), you have to modify in Settings:

• Authentication / Authorization
• App Service Authentication, "ON" =>> choose: Log in With Azure Active Directory
• Select 'ActivityProvider', base on your purpose. In my case, I'm using AAD.
• Configured (Express: Existing APP)
• Manage Azure Active Directory: Manage Permission & Manage Application

For Manage Permission ==>> Add, In Delegate Permission, choose: Sign in and read user profile and refresh your browser to login again