{"id":22697,"date":"2017-11-13T09:00:22","date_gmt":"2017-11-13T08:00:22","guid":{"rendered":"https:\/\/nolabnoparty.com\/?p=22697"},"modified":"2020-03-15T18:09:08","modified_gmt":"2020-03-15T17:09:08","slug":"veeam-fails-backup-azure-ad-connect-error-vss-critical-writer-has-failed","status":"publish","type":"post","link":"https:\/\/nolabnoparty.com\/en\/veeam-fails-backup-azure-ad-connect-error-vss-critical-writer-has-failed\/","title":{"rendered":"Veeam fails to backup Azure AD Connect with the error \"A VSS critical writer has failed\""},"content":{"rendered":"

\"veeam-backup-fails-azureadconnect-01\"<\/p>\n

The Veeam backup job of\u00a0Microsoft Azure AD Connect fails with the error A VSS critical writer has failed<\/em> ...Error code: 0x800423f4<\/strong>.<\/p>\n

The backup job window displays the error Failed to call RPC function \" Vss.Unfreeze\"...<\/em> for the virtual machine affected by the problem.<\/p>\n

\"veeam-backup-fails-azureadconnect-02\"<\/p>\n

To get additional details of the problem, opening the log file the error is related to the\u00a0SQL Server Writer<\/strong>, perhaps a Microsoft update somehow caused the issue.<\/p>\n

A VSS critical writer has failed. Writer Name: [SqlServerWriter].<\/p><\/blockquote>\n

The error reported in the Veeam log<\/strong> file.<\/p>\n

\"veeam-backup-fails-azureadconnect-03\"<\/p>\n

Same error in the Windows'\u00a0Event Viewer<\/strong>.<\/p>\n

\"veeam-backup-fails-azureadconnect-04\"<\/p>\n

To solve the problem, login to the Azure AD Connect server and go to the Control Panel<\/strong>. In the\u00a0Programs<\/strong>\u00a0category, click the link\u00a0Uninstall a program<\/strong>.<\/p>\n

\"veeam-backup-fails-azureadconnect-05\"<\/p>\n

From the programs list, select Microsoft SQL Server 2012 Express LocalDB<\/strong>\u00a0and click Repair<\/strong>.<\/p>\n

\"veeam-backup-fails-azureadconnect-06\"<\/p>\n

The program is being repaired.<\/p>\n

\"veeam-backup-fails-azureadconnect-07\"<\/p>\n

When the process has completed, the server must be rebooted to complete the procedure.\u00a0Click Yes<\/strong> to proceed.<\/p>\n

\"veeam-backup-fails-azureadconnect-08\"<\/p>\n

When the Azure AD Connect server has rebooted, run the backup job<\/strong> once again.<\/p>\n

\"veeam-backup-fails-azureadconnect-09\"<\/p>\n

This time the backup has completed successfully<\/strong>.<\/p>\n

\"veeam-backup-fails-azureadconnect-10\"<\/p>\n

This simple fix resolved the issue allowing to complete the backup job successfully ensuring the protection<\/strong> of the Azure AD Connect server.<\/p>\n

 <\/p>\n

Update 24\/11\/2017<\/h2>\n

The above fix seems not solving the problem permanently and, again, the issue is not due to Veeam<\/strong>\u00a0software but to an update of Azure AD connect.<\/p>\n

After a Google search, I found this article<\/a> in the Microsoft website that explains the issue:<\/p>\n

The user identity that is associated with the COM+ application is logged on when the COM+ application is first initialized. If this user were to log off of the machine then the user's profile would get unloaded and the COM+ application can no longer read registry keys in the profile of the user identity. Starting with Windows Vista the User Profile Service will force the unloading of a user profile when that user logs off. This is a situation where the functionality of forcing the unload of the user profile may break an application if registry handles are not closed in the process. This new User Profile Service functionality is the default behavior.<\/p><\/blockquote>\n

To fix the problem, login to your Azure AD Connect Server and open the\u00a0Local Group Policy Editor<\/strong> with the command\u00a0gpedit.msc<\/em>.<\/p>\n

\"veeam-backup-fails-azureadconnect-11\"<\/p>\n

Navigate to Computer Configuration > Administrative Templates > System > User Profiles<\/strong>\u00a0and select Do not forcefully unload the user registry at user logoff<\/strong>.<\/p>\n

\"veeam-backup-fails-azureadconnect-12\"<\/p>\n

Double click the selected item and thick\u00a0Enabled<\/strong>. Click OK<\/strong> to confirm.<\/p>\n

\"veeam-backup-fails-azureadconnect-13\"<\/p>\n

The option is now enabled. Reboot the server<\/strong> to complete the procedure.<\/p>\n

\"veeam-backup-fails-azureadconnect-14\"<\/p>\n

After rebooting, try to backup the server once again.<\/p>\n

\"veeam-backup-fails-azureadconnect-15\"<\/p>\n

The backup should now be completed successfully.<\/p>\n

\"signature\"<\/p>\n","protected":false},"excerpt":{"rendered":"

The Veeam backup job of\u00a0Microsoft Azure AD Connect fails with the error A VSS critical writer has failed ...Error code: 0x800423f4. The backup job window displays the error Failed to call RPC function \" Vss.Unfreeze\"... for the virtual machine affected by the problem.<\/p>\n","protected":false},"author":3,"featured_media":22698,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rop_custom_images_group":[],"rop_custom_messages_group":[],"rop_publish_now":"initial","rop_publish_now_accounts":{"linkedin_93tdZWzMZc_93tdZWzMZc":"","facebook_2879994398731222_17841400390232720":"","twitter_113568041_113568041":"","mastodon_115463926174894442_115463926174894442":""},"rop_publish_now_history":[],"rop_publish_now_status":"pending","footnotes":""},"categories":[903,2138,933],"tags":[1682,584,1426],"class_list":["post-22697","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vmware-en","category-backup-en","category-veeam-en","tag-azure","tag-veeam-en","tag-vss-en","has_thumb"],"_links":{"self":[{"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/posts\/22697","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/comments?post=22697"}],"version-history":[{"count":0,"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/posts\/22697\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/media\/22698"}],"wp:attachment":[{"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/media?parent=22697"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/categories?post=22697"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nolabnoparty.com\/en\/wp-json\/wp\/v2\/tags?post=22697"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}