How to stream from a Synology NAS from the latest version of the application ?

You should not have to reconfigure your library. My library connected automatically with the new app. Give resetting the app a try.

I don’t see an option to manage my “music library” under “your services” or “your sources” option.  Why would I need to use the windows or mac client to manage my library when I could manage from the iOS app directly before.  Is this capability ever coming back?  How do I add a network location via the iOS sonos app like I could before?  

PLEASE don’t ask about SMB v.x - running smb v.2 and have fully deprecated smb v.1…..

The release notes do not provide any level of detail to be helpful

There are not any. And I never said there was one. The 'Your sources' menu doesn't even appear, unless you accept that the application geolocates you. Completely crazy !
I completely agree with you, I don't like the current situation. Releasing a new application which, at a minimum, does not provide the same functionalities as the previous one, we call that regression. And that doesn't satisfy me.

I was just giving instructions, being the one who asked the question in the initial post and having solved my immediate problem. I absolutely do not agree with what Sonos has (or has not) implemented in this new version of the application!

Thanks for the follow-up.  I do have location services enabled when using sonos - I even turned it off and selected the prompt to ask when I use the app again - it prompted and I allowed it access when using the app - still don’t see my option for my library.

As mentioned by others - very poor implementation that requires sonos to know where I am just for me to access my local library.  That is the point of joining my managed network / subnet / authenticated.  Though I don’t see how to change network settings either after the update via the sonos iOS app.  I see an option under home - manage - network that talks about wifi (channels / bands / settings) but no way to actually connect to local network share.  I don’t use wifi for any sonos products - I use Port and it is Ethernet connected.

can’t connect to my local library via sonos iOS app - can’t connect to my local network via sonos iOS app - don’t even see an options to do so.

Trying to update/download the app for PC. You should see/be able to configure your library there.
I know it's not satisfactory but it's the only way to do it currently.
Back in your iOS app, you should see the 'Your Resources' menu with the library. If not, delete the iOS app and redownload it.

That's how I did it anyway.

Tried every trick in the forum. 

I'm sure my Synology NAS is using SMB2, changed the settings to only use SMB2. 

After that, reinstalled the pad to my music folder using the Android App after deleting the old pad using de pc app. 

After that I sometimes get my music library but I cant browse it without a error. 

I can use it on the pc, thats still the same as earlier.

After the error in de music library, it completely disappeared in my options on the app. The only way to get it back is to reinstall the app, delete the pad again en install it again. But then always that error. 

Sonos, get your s*** together. 

Moderator Note: Modified in accordance with the Community Code of Conduct.