When I set up an eB EQL Datasource in SSRS, I can connect to eB using the ADMIN user credentials, but when I try to use Windows Authentication I get this error:
Could not load file or assembly 'Microsoft.IdentityModel, Version=188.8.131.52, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)
This version of eB does not come with the Windows Identity Framework. It is also not documented in 15.4 that WIF installation is required.
You need to ensure that WIF 3.5 is installed in this version of .NET (Prior to 4.5) WIF is a separate installable component. Post 4.5 WIF is now part of the .NET deployment.