Fix error 0x8007007A downloading Offline Address Book in Outlook

Microsoft 365 users may receive Fix error 0x8007007A downloading Offline Address Book in Outlook (OAB) for profile in Outlook on Windows 11 or Windows 10 computer. If you experience this issue, this post provides solutions that you can apply to quickly fix the error.

When you configure an Outlook profile using the Office Customization Tool (OCT), you may encounter an error if you select the Enable offline use option, but you did not specify the directory path to store the Offline Address Book files.

Error 0x8007007A when downloading Offline Address Book in Outlook

If you’re encountering the Outlook error 0x8007007A when downloading the Offline Address Book, you can try any of the recommended solutions below in no particular order.

1. Check the directory path of the OAB file
2. Create new Outlook profile
3. Modify Registry

Description of process involved in each solution listed:For each solution, let’s take a look at the description of the process involved. This will help us understand how each solution works and how it can best be used to solve the problem at hand.

1] Check directory path of the OAB file

To fix the 0x8007007A error when downloading the Offline Address Book in Outlook on your Windows 10/11 PC, you need to check the directory path of the OAB file. The location of this file depends on the version of Outlook you have installed.

To check the directory path of the OAB file for Outlook 2013, do the following:

• In Office 2013, click Add accounts under the Outlook section in the OCT.
• Click the account you want to configure.
• Click on the “More Settings” option.
• On the Cached Mode tab, select the option to configure Cached Exchange Mode.
• Select the “Use Cached Exchange Mode” option.
• Select the Customize location for .ost and .oab files option.
• Check the directory path to store offline address book files text box.

Do one of the following and click OK:

• In the “Directory path to store Offline Address Book files” text box, enter a valid path.
• Uncheck the “Customize location for .ost and .oab files” option.

To check the directory path of the OAB file for Outlook 2010, follow these steps:

• In the Office 2010 OCT, under the Outlook section, click Add accounts.
• Click the account you want to configure.
• Click on More Settings.
• To enable offline use, select the Exchange tab, then select the Enable offline use option.
• Make sure the “Directory path to store Offline Address Book files” text box is checked.

Now, do either of the following and click the OK button:

• Use the “Enable offline use” option to make your offline experience better.
• In the “Directory path to store Offline Address Book files” text box, enter a valid path.

2] Create new Outlook profile

Related Post: problem with the proxy server’s security certificate – Outlook error

In order to fix Error 0x8004010F, Outlook Data File Cannot Be Accessed, you will need to create a new outlook profile. To do this, follow the instructions in the guide.

3] Modify Registry

Outlook cannot store the OAB files successfully, and the error in view can occur if the value data for the 001e660e registry entry is missing. This solution requires you to delete the registry entry in question. Since this is a registry operation, we recommend that you create a backup or restore point before proceeding.

To open the Run dialog, press the Windows key + R on your keyboard.
Type regedit in the Run dialog box and press Enter to open Registry Editor.
Jump to the registry key path below depending on the version of Outlook installed on your Windows 11/10 PC. Replace the placeholder with your actual Outlook profile name.

For Outlook 2013:

HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Profiles\

For Outlook 2010:

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\

• Click on the Edit menu at the location.
• Select Find.
• Now, enter the registry key “001e660E” into the search field to search for it.
• Select Find Next.

The result should be displayed under the correct subkey. To view the data of the 001e660E registry value, check if it is blank. This may be the cause of the OAB download issue.

Now, delete the registry key by right-clicking it and selecting Delete from the context menu.

You can take ownership of the registry key and try the delete operation again if you’re unable to delete the registry key.

• Exit Registry Editor when done.
• Reboot PC

How do I force an Offline Address Book to download?

In Outlook, you can force an Offline Address Book download by doing the following:On the Tools menu, click Send/Receive. In the Offline Address Book dialog box, check Download changes since last Send/Receive. Click OK.

How do I troubleshoot the Outlook Offline Address Book in an Office 365 environment?

Here are some troubleshooting suggestions for the Outlook Offline Address Book in an Office 365 environment:

• Make sure the Global Address List (GAL) is up to date.
• Download the Offline Address Book manually, and then enable Cached Exchange Mode.
• Please ensure that the Background Intelligence Transfer Service (BITS) is running on your Windows 11/10 PC.

Why does Outlook default to Offline Address Book?

The default configuration for Outlook is to use Cached Exchange Mode, which is why the Offline Address Book is set as the default. Cached Exchange Mode is more responsive than the online version, so using the OAB by default makes sense.