I recently deployed a new Exchange Server 2013 Standard environment. All has been smooth for about 6 months and all of the sudden, I can't access ECP or OWA. First thing I check is the Forms Based Authentication Service, but it's gone. No idea where it went, or how to get it back. I haven't found a post on the same issue?

Anyone no how to repair this issue?

Thanks!

Hi Dean,

I don't think we have a service by the name of MSExcahngeFBA in Ex2013. Please check the logs for more details on issues with the virtual directories.

Use Get-OwaVirtualDirectory  and Get-ECPVirtualDirectory cmdlets to check the status.

You might have to recreate the frontend and backend virtual directories if nothing works out.

https://support.microsoft.com/en-us/kb/2871485#/en-us/kb/2871485

Run this to confirm all the required services by Exchang are running fine:

Test-ServiceHealth

RequiredServicesRunning : True

Hi,

I have not found the Forms Based Authentication Service in my exchange server 2013.

I think the issue  is not related to the servics.

Have you make any changes recently?

Please post the detailed error message here.
You can try to  reset the OWA and ECP virtual directory to test.
If the issue persists, please check some related logs for further analysis.

Regards,

David

Check the application, system logs and IIS logs. You may find something here.