Microsoft 365 Integration stopped working all of a sudden

[cpe90]

Hi all,
Has anyone else had issues with Microsoft 365 integration stopped working just recently?
The last time I could connect to the admin page using my AD credential was last Saturday or Sunday.
But today, for some reason, I no longer have that ability.
When I look at the admin dashboard/settings/Office 365, I see the following error:

Access denied. Please check if Application ID is correct and public key is uploaded to corresponding application in https://apps.dev.microsoft.com.
It might be a temporary issue. But you can try to re-provision the connection.

When I tried the re-provision by typing in my admin account info, it just sat there with the status "waiting for settings to take effect.." for hours.
I wonder if something changed on October 1st with how 3CX and Microsoft communicate.
Anyone else here having the same experience?


Appreciate the help, guys.

 

[Alejandro_3CX]

If you were using the O365 before the sp8, then the same must be reprovisioned as shown in this guide

Be sure you are logging with the your Azure admin account to authenticate the app creation on Microsoft 365

 

[cpe90]

I did all the way to step 5, and it just stuck here ...




We are running 18.0 (Build 939)

 

[Alejandro_3CX]

status is ok https://status.office365.com/ this might be a network issue, did you try using a different connection to see if there is any change?

 

[cpe90]

Okay, let me try that.
Thanks.

 

[cpe90]

Unfortunately, I'm not able to switch to our secondary ISP, as a lot of people are currently online.

May I know what ports are being used by this O365 integration so I can investigate our firewall logs?
I did run the firewall test on 3CX, and they are all pass.

 

[cpe90]

I just want to update the thread.

I have finally fixed the issue.
The problem was the date/time on the 3CX appliance was out of sync with the correct date/time.
Even after multiple restarts or shutdowns, it will not resync with the ESXi host.
I noticed in the dashboard/system status that the time was off by 5 hours but the timezone under settings/language & office hours is set up correctly to our CST time zone.
As a workaround, I changed the timezone to Hawaii zone so at least we can get by during the day.

During the maintenance time last night, our 3CX partner helped install the NTP server/client manually on the Debian OS of the appliance and enabled it.

These are what we did:
apt-get install ntp
timedatectl list-timezones
sudo timedatectl set-timezone "Your TimeZone".
sudo apt-update ntp

Once the time sync issue was fixed, the Microsoft Office was reconnected again.

Why, all of a sudden, the appliance went out of sync and stubbornly won't sync with the ESXi host is still beyond me. Maybe 3CX support can let us know.