Iphone : Import Key when connecting

Hello

With the recent major iOS updates (it seems), now our iPhone users cannot connect anymore using the Mattermost app.

The Mattermost-Classic app works though.
The Web and Android versions work.

The problem is that after entering the address of our self-hosted server, they are asked to IMPORT KEY (see picture)

I find absolutely no information about that screen.

Then it sometimes crashes

Versions:
iOS 13.2
mattermost 1.24.0

Server: on Docker, behind our provider’s NGINX RP (and of course the NGINX docker RP)
Version: 5.16.0
Build Number: 5.16.3
Build Date: Wed Nov 6 14:03:24 UTC 2019
Build Hash: 533c7bb3e5847db423387abfcf983e3f947818eb
Build Enterprise Ready: false
DB Version: 5.16.0

Please if anyone has info!

Thank you

Hi @bibelo, is this happening to every user on iOS? Also, could you let us know what happens when you select ‘Import Key’?

If you are on HTTPS, is your Mattermost server using a self-signed or CA-signed cert?

Hello and thank you for your answer.

All users but one have this behavior. They are all on the same version of iOS and MM app.

I asked the user where it works, but he told me he didn’t do anything different (he’s the boss so I don’t believe him ^^)

They can’t do anything on the Import Key screen except cancel. I guess they have to type in something but I don’t know what.

The way it’s working is:
Our provider has a NGINX RP, on which our HTTPS certificat is installed.
The certificate is CA-signed, valid until 2020 for all our sites.
Our provider had to add specific rules on their RP for notifications to be received by apps or www versions of MM. It worked fine for months.

Behind our provider’s RP, the communication is plain HTTP to our server where MM server is installed with Docker (thus 3 containers: www, app and db).

The server was on version 5.9 and it stopped working with the last iOS update. Then I upgraded the server to 5.16 hoping it’d solve the problem but issue is still here.

It works fine on all Android apps and Web versions.

Thank you in advance.

Please Do you have ideas as to what is the cause of the problem?

it seems the app was crashing and not all the users had updated their iOS.

Most of them are now OK except one or two.