iOS 11 Compatibility

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Does Microsoft expect to have Day 0 compatibility with iOS 11 for the Skype for Business mobile app?  Any known issues that enterprises should be aware of as we prepare to announce support for iOS 11 to our users?

14 Replies
Hi Nicholas,

I’m running public iOS 11 beta on my iPhone. I’m not facing any issues with the Skype for Business and Skype for Business Preview apps at the moment. (Using one for on prem and one for online)
Same here: iOS11 beta with SfB Preview Client (Online deployment), and zero issues. If anything, the experience is better than GA.

Hi Erwin


I'm using IOS 11beta on my iPhone 6.  The standard Skype for Business app doesn't work.  I'm waiting to be accepted for the SkypePreview program, still pending.  Am I reading you correctly that you are not having any issues with the standard app?  Thanks in advance - I'm dead in the water until I have a resolution...



Hi Tim,

I’ve a iPhone 7 with the latest iOS 11 public beta (from yesterday) and both clients are working perfectly (sfb and preview sfb).

Thanks Erwin - Since it is working for you, I deleted the app, then installed the newest IOS beta.  Reinstalled sfb and all is well.  My sfp preview status is still pending approval.



I am facing the same issue in my organization. Those users who have upgraded their devices to iOS 11 and above are facing s4b connectivity issue.
Have you tried to reinstall the app?
Yes, I did on 3 to 4 devices. Some has ios 11.0 and some has 11.0.1.
So far 20 users in my organization have upgraded to 11.x version. We have sent the notification to all the users that before upgrading you might face S4B issue. :|

Hi, same here. After iOS 11 upgrade nobody in my organization can connect to S4B. Reinstall has no effect...

Any updates on this for people running 11.0.1?  We have some client environments where users can connect and other environments that can't, and so far I don't see a reasoning for the failure, without digging into the IIS logs.

I may have found a possible solution, hopefully the rest of you can test and verify.  The clients IIS ARR server was set to a timeout of 960 (16 mins) for some reason, I always prefer as setting of 1200 or higher.  Since changing to 3600 from 960, the iOS 11.0.1 based Skype Mobility client isn't getting signed out after 10 mins, and blocked from signing in again.  Some blog articles use a 200 sec setting or even 300, which with Skype connections, is never good.  20 mins or higher, including HTTP traffic, is I think always the minimum.  Some weird firewalls its actually needs to be 45 min for odd reasons.

Our corporate environment was already set to 30 mins, which is why I believe those users didn't have issues.

Please let me know what you find and if changing it to 1800 resolves or not.

Hi Korbyn,


Thanks for your reply. Where exactly you made these changes? On which application pool of IIS? I am using Kemp VLM as a reverse proxy for S4B mobile and i have increased the timeout limit on Kemp but not sure where else should i need to do it.....


By the way, even after upgrading the iOS to 11.0.3, the users are still unable to connect S4B.



I only had to increase on the reverse proxy servers, IIS ARR in our cases.  Kemps are usually at 20 mins, or should have been already, but they're a little more hard core, so you may need to make sure the firmware is up to date on the Kemp's.  Could also try bumping to 30 mins.  Are there any other firewalls in that path, before or after the Kemp? 

I also use IIS Crypto from Nartec as well to clean up the Cipher's and disable SSL 2.0 and 3.0, which may also be a combined effect with increasing the timeout to 1800s or more.

Every time Apple comes up with a new iOS, they find fantastic new ways of mucking up encryption.

Hi Ather,

did the suggested solution solved the problem?

We are running IOS11.1.2 (15B202) and SfB, and still have the same problem as you.

regards James