Web.Config modifications due to Join Launcher change

Another new change in CU-277 is a new flag allowCrossDomainRequests=”true” added to the Web.config file as per KB3209567  Unfortunately, they failed to mention which one(s).  As it turns out, there are 60 web.config files in the Skype for Business installation folder, or at least there is in my installation, and all under Web Components.

The following folders contain a web.config file with allowCrossDomainRequests=”true” setting present in it.

Autodiscover\Ext
Autodiscover\Int
Join Launcher\Ext
Join Launcher\Int
UCWA\Ext
UCWA\Int
Web Ticket\Ext
Web Ticket\Int

Now, it seems that it doesn’t modify the file, but replaces the file and what is partially confusing is the last modified date of these file.  Join Launcher has a modified stamp on Dec 22, 2016 and UCWA is modified Oct 12, 2016.  The AutoDiscover and Web Ticket files date back to 2015 so not any recent changes.  It seems that regardless that the Join Launcher web.config is the only newly modified one, others are replaced as well.

Why I bring up the date, is I modify the UCWA web.config files, I change the key value for MobileApplicationExpiryTimeInDays from 15 to 1.  There was an issue with Skype Mobility clients and Call Forwarding would “break” because the server thinks the Mobile Client is still signed in so the Forwarding or SimRing to the mobile number won’t take place.  The setting change kicks the Mobile Client after 1 day, instead of waiting 15 days before timing out the client, and the problem because less noticeable.  Actually I haven’t had a complaint since.  We never could lock down when the issue would start, either the client was being updated when it was already signed in, or moving from internal to external networks, but something would happen that would change the client ID associated with that device, so even signing in and signing out didn’t matter as the registered ID on the server was new.  Why 15 days, no idea.  1 day works great and no negative consequences that I’ve ever detected.

If anyone has any other customization that they made to a web.config file, you may want to review them and see if they’ve been over turned.

That is actually one of my most favorite quotes, and probably from one of the best Futurama episodes, Godfellas.

4 thoughts on “Web.Config modifications due to Join Launcher change”

  1. Customized web.config (or whatever they named after the executable name in some cases) files in Exchange or Lync/Sfb are ALWAYS subject to termination and replacement if you or WSUS applies a new CU. So best practice to ALWAYS backup ALL such config files and do compare ALL of them after the CU installed. Yes, wastes much time… but thats how life (and sfb consultants) keeps busy by MSFT.

  2. Wait a minute…just to make sure that I’m understanding your post, you’re saying that modifying the web.config will eliminate the issue with mobile clients (and the new S4B Mac client) having a static registration that lasts 14 days, even though the client is no longer signed in?

    We’ve had a case open with Microsoft on this for awhile because of the known issue of where it looks like someone is online, but in reality they aren’t signed in anywhere (and might not have been for several days), you send them an IM, and it tells you that it can’t be delivered.

    We’ve also had some issues where someone is in fact online on their desktop client, they have an old static mobile registration, and the server picks the mobile device instead of the desktop device to send the IM, call, screenshare, etc. to.

    If this shortens that time frame, this is fantastic! MS told us pretty much there’s no way to get rid of or shorten the length of the registration besides actually pressing the sign out button on the device. It’s made for a terrible UX.

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