User is unable to log into RD Web Access using AuthAnvil credentials but there are no errors showing up in the AuthAnvil event or server logs.
When downloading RD Web Access, sometimes the DLL included in the package will be blocked. This causes all RD Web Access logins that are supposed to authenticate with AuthAnvil to return "AuthAnvil was not able to authenticate using your credentials"
Navigate to C:\Windows\Web\RDWeb\Pages\Bin. Right-click on the AuthAnvil.dll, go to properties, and click "Unblock" at the bottom of the dialog box. This will permit the DLL to run as expected. After, you will need to run an iisreset.
RD Web Logon Agent