Cannot Add Guest Team Member to Private Channel

[arrthurr1111]

This is a strange issue…

I have 48 Guest users spread across 14 teams; some of these Guests are part of more than one team, and these this setup has been running without issue for about six months.

I recently setup private channels in each of my teams and began adding relevant Guests, but some Guest members no longer appear in the directory listing when adding members. For example: Joe User (Guest) is a member of My Team, but when I attempt to add him to My Private Channel, I can see other members in the dropdown list (including other guests), but not Joe. This affects 6 guest members across private channels in three of my teams, and to be clear: all of my teams have private channels, and all of those private channels include a subset of all of my guest users. 

And if that's not strange enough: Joe User (Guest) can be added successfully to *some* private channels, but not others, so the issue doesn't lie with a particular guest or a particular channel/team. I can't figure out a pattern. Has anyone ran into an issue like this? I'm well below any thresholds on channel limits or guest user limits, too.

[#2 · Accepted solution]

Hi @arrthurr1111

See this article

https://techcommunity.microsoft.com/t5/microsoft-teams/can-t-add-members-to-private-channels/m-p/103...

- What about removing the user from the Team and re-adding them?
- What about trying it from the mobile app?

Let me know how you get on?

Best, Chris

[#3]

Joe User other private channels in the same Team or different Teams? Sounding sort of like a cache issue but hard to tell, as Hoard said, try via Mobile and or Web Client to elminate that.

[#4]

Yes — mobile app exposed the guest users I needed. Also, something to note, updating Teams.app on desktop did not solve the issue. The deeper I got into web/desktop clients, the more I forgot about testing on mobile.

[#5]

@Christopher Hoard YES – mobile (iOS) app exposed my guest user!

Thanks for that thread; it's the one I'd been searching for – I knew I couldn't have been the only one affected. 

[#6]

I’d log out of teams (not quit) and log back in. This clears most cache issues and see if it then let’s you add them on desktop client.

[#7]

Crazy; it still doesn't expose the "missing" guest user.

- Logged out; logged back in (desktop)
- Went to team where I successfully added "missing" user via mobile app
- Attempted to add *that* user to different private channel
- "Missing" user is still missing from the "add member" list

It can't be an AAD issue; the guest is validated. It can't be the Team or channel; the "missing" user was added via the mobile app (which is what you'd expect not to work). And it can't be the guest user (even in the private context); I've got "missing" users that have been added to other private channels in different teams.

All that said, for this to work for me (at all) this soon after the private channel rollout has been a success; this issue has only affected 1% of my Guest users. And thanks to the mobile client, it's really a non-issue, just a workaround.

[#8]

Yeah just gathering data so I can report it to the Team if needed. Could you try the teams.microsoft.com web client and see if issue is there as well?

[#9]

@Chris Webb Same behavior; cleared cache and removed specific cookies from Chrome 79 (*.microsoft.com, *.sharepoint.com etc). I opened an Incognito window for the fun of it; no change. 

[#10]

@arrthurr1111 , I knew I wasnt the only one with this issue! I was finally able to add the new external guest members to the private channel through the mobile app.  

[#11]

I experienced the same, some users don't show up for addition to private channels, but I could add them in the Android app. 

[#12]

@arrthurr1111 

I'm glad I found this thread.  I've been pulling my hair out trying to figure out whether the issue was on my side or my guest's side setup.  Apparently it's on neither.  I never would have thought it would work on the mobile app and not desktop,  Also, adding large batches of emails from excel is on the desktop.

Thanks everyone for the comments and links!

Very helpful. 

[#13]

@arrthurr1111 So it seems that Private channel owner may be trying to add the guest by complete address - user@domain.com. Can he try to add the guest by display name instead or by searching just searching partial display name ? I am seeing similar behavior in my test tenant where if the keyword is display name the search succeeds but fails for the full address.

[#14]

@arrthurr1111  Figured this out for those who need to know like I did.  I was able to add my Gmail account as a Guest to the root Team, but not sub channels, UNTIL I registered my Gmail account with Microsoft, creating a Microsoft account named my Gmail account.  Once this registration was completed, the Online, Mobile App, and Desktop App all were able to find and add my Gmail named Microsoft account to the Channels.

In short, Teams is waiting on the guest user to register, THEN you can add the registered Microsoft account to Channels. Those that appear immediately have likely registered previously for services such as Microsoft Store or other products requiring a Microsoft account.

EUREKA! :D

[#15]

I've figured out a direct solution to the issue, facing the same problem myself when we wanted to invite guest BETA testers to interact with and get feedback directly. The idea of deleting and re-adding the Team sounded ludicrous to me, so I kept trying to figure it out.

I was able to find a sequence that works consistently and is a direct solution to the problem you're all facing. I perform some of my steps in the Teams Desktop App and some in the Teams Admin Center. You'll need appropriate permissions, I'm a Global Admin for the domain. I'll post my steps in order:
Create a new Team in the Teams App. I created a Microsoft 365 Group for group email distribution, but I believe it will also work setup as a regular blank Team.
Once the Team appears in the App, create your custom "Private" Channel. 
Click on Manage Team and add a new Member. Enter the Guest's email address, and edit their display name prior to finalizing. Do this for all Guests. Remember, you're adding to the TEAM ONLY.
This is usually where adding the newly created user to the Channel fails.  Do not waste your time here any longer. Open the Teams Admin Center and navigate to the Channel itself. 
Teams Admin Center.
Teams.
Manage Team.
Click the Team name itself.
Click the Channels Tab.
Click the Channel Name.
Click the Add button.
Type in the guest user's Display Name.
Select and Apply.
Return back to the Teams App, within a few seconds you should be able to verify that the Guest is a Member of both the Team and the Private Channel.
You're done.
This should work consistently; I've used this method on three Teams and across 6 Private Channels now. Good luck everyone!

[#16]

Thanks! once guest registered, i was able to add to private channel