We are here talking about the error with active sync when you are updating the Exchange Server. In the last step, Mailbox role: Client access front end service, you receive the error about active sync virtual directory.
I found the following link that help me. https://social.technet.microsoft.com/Forums/en-US/5ea988d8-c792-448d-9642-3dca623af5e4/troubleshooting-8220xxx-virtual-directory-already-exists8221-issues?forum=exchangesvradmin But, I need to change the last step. So, I downloadded the IIS Resource Kit to delete the Microsoft-Server-ActiveSync from Root, 1, W3SVC, LM.
After, We removed the CN=Microsoft-Server-ActiveSync (Default web site).
And re run the setup /m:upgrade
After completed, please create the active sync virtual directory in Default web site.
Reference https://social.technet.microsoft.com/Forums/en-US/5ea988d8-c792-448d-9642-3dca623af5e4/troubleshooting-8220xxx-virtual-directory-already-exists8221-issues?forum=exchangesvradmin
UC Steps 