While trying to register my CRM instance in Azure Active Directory, I noticed that the Azure portal started to throw an error regarding the fact that I didn’t have access to do so, even though I had Admin privilege. After searching on blogs, I found a couple answers saying that you have to change some things in the User settings on Azure, however this didn’t work for me.
In my case, the problem resides in the fact that I was loggin into Azure portal with the wrong credentials(Personal) and in order to have access to Azure Active Directory you have to log in with the same tenant credentials used for your CRM instance. I know this might be something obvious but I believe this could help more than one in the future.
Hope it helps.