Very recently, Microsoft retired the regional discovery service . This broke my connection to all of my custom SSRS reports in Visual Studio–I started getting authentication errors for each report. What a pain! So, if you start getting authentication errors in Visual Studio, but you know the credentials are correct, try this. (Kudos to Kelsey @ The Marks Group for this fix)
Download the most recent report authoring extension file, but do not install it yet:
https://www.microsoft.com/en-us/download/details.aspx?id=56973
Search for “Add or remove programs” in Windows, select it:
Search for “report authoring” or “Dynamics”–you should see “Dynamics 365 Report Authoring Extension in the results list. Click on it, then click “Uninstall”, and proceed through the uninstall wizard.
Now you should be able to install the report authoring extension file you downloaded in the first step. Good luck!