Files to backup on Exchange 2016 before installing a CU

[Deleted]

New to Exchange 2016. In the past with Exchange 2010, before installing a CU I would backup certain files which I believe were in C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\Owa\"version"\themes\resources

Version of course being that last folder created by the CU.

Is the path different in Exchange 2016? I realize everyone has different files and customizations to save but I'm just trying to narrow it down to a folder path. The last person that did this did not document this information such as customized logo's for OWA etc.....Also, I read that with Exchange 2016 CU's, The install automatically creates a backup of the web.config files in all the folders. Is this true?

Any help would be appreciated.

[#2 · Accepted solution]

if you are enquiring about files for the customisation of OWA etc, then the details are here: https://learn.microsoft.com/en-us/exchange/clients/outlook-on-the-web/customize-outlook-on-the-web?v...
If you are talking about themes, then the details are here: https://learn.microsoft.com/en-us/exchange/clients/outlook-on-the-web/themes?view=exchserver-2019

I'm not sure that a CU install performs any backup. The Microsoft site detailing the CU install process says that no customisations survive the install process.