Hello all, I am not sure if posting question in right place, but hope someone can help me with this as I didn't found any answer on web.
I am trying to update Exchange 2013 CU9 to CU 23. All prerequisites' are done and fine with that. But When I try to install I am getting this error in the step when coping files are started at 24% it gives this error:
Installing product E:\Exchange 2013-CU23\exchange server.msi failed. Fatal error during installation. Error code is 1603. Last error reported by the MSI package is 'The installer has insufficient privileges to access this directory: C:\Program Files\Microsoft\Exchange Server\V15\FrontEnd\HttpProxy\owa\auth\15.0.1497. The installation cannot continue. Log on as administrator or contact your system administrator.'
I am using Admin account with all the required access rights. Also I have checked that path shown above and find out there is no 15.0.1497 folder inside auth folder. There is folder 15.0.1104. Also after this all services are disabled and can't run even the CU9 that was working normal. So we are restoring vm from last backup.
Please if you can help me how to update 2013 CU9 to latest version we are planning to migrate to 2016 so need at least CU10.
Thanks in advance.

