As with every second Tuesday of the month, Microsoft released its regularly scheduled Windows updates yesterday. Update KB2817630 for Outlook 2013 caused issues for a number of people, and Microsoft has pulled the patch. Microsoft posted an explanation of what went wrong on their Office Blog today:
Due to a version incompatibility between outlook.exe and mso.dll, a mismatched reference to a data structure causes the “Minimize” button in the navigation
pane to render incorrectly, typically extremely large to the point that the navigation pane is “invisible” to the user. The issue only manifests when incompatible versions of outlook.exe and mso.dll exist on the system.
If both versions are earlier (lower) than 4535.1000, or both versions are later (higher) than 4535.1000, the problem does not manifest. If one file is updated but the other is not, the problem is evident. The incompatible state is created by installing either the September Public Update OR the August Cumulative update, but not both. Users of MSI-based products that have automatic updates enabled are those that are most likely to have encountered the issue.
Office 2013 Click-to-Run products are not affected.
Office 2013 Versions Affected
- Office 2013 Standard
- Office 2013 Professional Plus
Said differently, only MSI installations of Office or Outlook 2013 are affected. These are volume-license installations typically found in businesses that
purchase licenses in volume.
Each version of Office installed, such as viewers, standalone client products, Office suites with MSI-based installations, etc., will receive the update. We have
seen reports of some users needing to remove the update two or 3 times. This is because the system has product ID’s for multiple installations of MSI-based
Office products.
Office 2013 Versions that are NOT affected:
- Office 2013 Home & Student
- Office 2013 Home & Business
- Office 2013 Professional
- Office 365 Home Premium
- Office 365 Professional Plus
- Office 365 University
- Office 365 Small Business Premium
- Office 365 ProPlus
- Office 365 Enterprise
How to fix affected installations:
Two updates can get a user into this state. Installing the September Public Update delivers an updated version of mso.dll without updating outlook.exe, resulting in the incorrect user interface.
- If you have Automatic Updates enabled, visit the Add Remove Programs feature of your Windows Installation, and uninstall KB2817630. Close Outlook and restart.
- If you have installed the August Cumulative update (which you must do manually), removing KB2817347 will correct the issue. From the Add Remove Programs feature, select KB2817347 from the list and select “Uninstall.” Close Outlook and restart.
- If you have BOTH Updates installed, the problem is not evident. The issue only manifests when one of the updates has been installed. If you have updated to the September Public Update and you want to roll forward, install the August Cumulative update, KB2817347.
Read the full post at The Office Blog