Hello @Don Mason,
Thank you for posting your query on Microsoft Q&A.
Based on your description, it seems you are encountering a blank login screen when modifying Azure AD Connect settings or during installation. To ensure we're aligned, I've attached a screenshot for clarification.
Unfortunately, there isn't a direct solution for this issue; it requires investigating several factors to determine the root cause. Additionally, this doesn't seem to be strictly related to an Entra Connect sync issue.
Here are a few steps you can try:
- Can you log in to portal.azure.com using Edge on that server? If yes, also try logging in to login.microsoftonline.com from Edge.
- If the logins work on Edge, make sure to set it as the default browser on the server.
- Change the IE Enhanced Security settings to “No.”
- Ensure TLS 1.2 is enabled on the server. You can refer to this documentation for a PowerShell script to verify TLS 1.2 settings.
- Is per-user MFA enabled for the account? If so, temporarily disable MFA and check if the issue persists.
- If disabling MFA resolves the issue, make sure to add the required URL for MFA to the trusted sites list:
https://secure.aadcdn.microsoftonline-p.com
- Open
inetcpl.cpl
, navigate to the Security tab, and adjust the security level settings to “Low.” Then, test again.
If the issue isn't resolved after any of these steps, please Let me know how it goes.
I hope this information is helpful. Please feel free to reach out if you have any further questions.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Thanks,
Raja Pothuraju.