Follow-up: Possible ZCO Build 1951 Bug (included in Patch 10.1.17)

[Randy Leiker]

Everyone,

Following-up on this topic, I have done more testing to narrow down what appears to cause the bug in ZCO Build 1951 that crashes Outlook Classic upon start-up and have posted the steps to reproduce in the Zimbra Forum: https://forums.zimbra.org/viewtopic.php?p=318342#p318342

Since I shared this info back on May 30th, I have deployed patch 10.1.17 on a number of my professional services clients' Zimbra clusters and single server installs so far, with no other issues to report.  If you are hesitating to deploy 10.1.17 on your own Zimbra infrastructure due to this possible ZCO bug, I suggest proceeding with the 10.1.17 patch to remediate the known security vulnerabilities, and if you have any Outlook users with 2FA enabled mailboxes, simply roll-back to ZCO Build 1950 post-installation of patch 10.1.17 using the steps here: https://wiki.zimbra.com/wiki/Zmupdatedownload .  You can either save a copy of ZCO Build 1950 by downloading it from your own Zimbra server prior to patching, or obtain it by visiting https://www.zimbra.com/product/addons/zimbra-connector-for-outlook-download/ and changing the download URL:

From:
https://files.zimbra.com/downloads/zco/1951/ZimbraConnectorOLK_1951_x64.msi
https://files.zimbra.com/downloads/zco/1951/ZimbraConnectorOLK_1951_x86.msi

To:
https://files.zimbra.com/downloads/zco/1950/ZimbraConnectorOLK_1950_x64.msi
https://files.zimbra.com/downloads/zco/1950/ZimbraConnectorOLK_1950_x86.msi


Randy Leiker ( randy at skywaynetworks.com ) 
Skyway Networks, LLC 


----- Forwarded Message -----

Hi Everyone, 

I installed Zimbra patch 10.1.17 this evening on a Zimbra cluster. The patch appeared to install successfully and services restarted fine, however I did encounter a possible bug with ZCO build 1951, that is included with patch 10.1.17 and wanted to post a cautionary note here as a heads-up, so you can verify if this is an issue in your environment too. I'm re-posting this on the Zimbra Forum too. 

I opened Outlook 365 Classic on a Windows 10 test machine that has an existing Zimbra profile running ZCO 1950. The Zimbra mailbox for this Outlook profile has 2FA enabled. After entering the 2FA code, Outlook opens and it correctly prompts to upgrade to ZCO 1951. After allowing it to upgrade to build 1951, the installer exits, and Outlook Classic automatically restarts, and the Outlook splash screen appears. However, instead of displaying the expected 2FA prompt, Outlook appears to crash as the Outlook splash screen disappears & there is no longer any outlook.exe process running. I also did an uninstall of ZCO 1951, then manually re-installed it from [ https://www.zimbra.com/product/addons/zimbra-connector-for-outlook-download/ | https://www.zimbra.com/product/addons/zimbra-connector-for-outlook-download/ ] and received the same result. Uninstalling ZCO 1951 and rolling back to ZCO 1950 fixes the issue, allowing Outlook to again correctly prompt for the 2FA code and launching successfully. I made no changes to the Outlook profile while testing. 

In the event this is later confirmed to be a bug in ZCO 1951, I rolled back to ZCO 1950 on the server-side ( [ https://wiki.zimbra.com/wiki/Zmupdatedownload | https://wiki.zimbra.com/wiki/Zmupdatedownload ] ) to prevent all hell from breaking loose when users start-up their Outlook apps on Monday morning & would otherwise begin upgrading to 1951. 


Randy Leiker ( randy at skywaynetworks.com ) 
Skyway Networks, LLC 

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