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.