{"id":2016,"date":"2017-01-10T19:23:38","date_gmt":"2017-01-10T19:23:38","guid":{"rendered":"http:\/\/microsoftgeek.com\/?p=2016"},"modified":"2017-01-10T19:27:03","modified_gmt":"2017-01-10T19:27:03","slug":"o365-to-exchange-on-prem-migration-error","status":"publish","type":"post","link":"https:\/\/microsoftgeek.com\/?p=2016","title":{"rendered":"O365 to Exchange on-prem migration error"},"content":{"rendered":"<p>When you attempt to migrate an O365 user back to Exchange 2010 on-prem you may receive this error:<\/p>\n<p>&nbsp;<\/p>\n<p>&#8220;You shouldn&#8217;t migrate mailbox &#8216;Paul Demmer&#8217; to Exchange 2010 or an earlier version while the user&#8217;s Instant Messaging contact list is stored in Exchange. If you do, the user could permanently lose access to their Instant Messaging contact\u00a0list, which will cause serious data loss. The Exchange copy might be the only copy of this user&#8217;s contact list. To continue, please contact your Instant Messaging administrator and make sure that the user&#8217;s contact list is moved back to\u00a0the Instant Messaging server. After this has been done, you should be able to complete this migration. If you must migrate the mailbox despite the potential data loss, you can do so by running &#8216;Set-Mailbox mailboxID -ImListMigrationCompleted $false. &#8221;<\/p>\n<p><a href=\"http:\/\/microsoftgeek.com\/?attachment_id=2017#main\" rel=\"attachment wp-att-2017\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-2017\" src=\"http:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate.png\" alt=\"unabletomigrate\" width=\"984\" height=\"618\" srcset=\"https:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate.png 984w, https:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate-300x188.png 300w, https:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate-768x482.png 768w\" sizes=\"auto, (max-width: 984px) 100vw, 984px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>The cause of this is the following:<\/p>\n<p>This occurs if the Lync 2013 contacts of the user who is associated with the mailbox are stored in the unified contact store in Exchange. By default, if the user signed in to Lync 2013, the unified contact store is enabled for that user. Additionally, the user&#8217;s Lync contacts are migrated from the Lync server to Exchange.<\/p>\n<p>&nbsp;<\/p>\n<p>SOLUTION<\/p>\n<p>In Power Shell run as Administrator:<\/p>\n<p>Use the\u00a0<b>Set-Mailbox<\/b>\u00a0cmdlet together with the\u00a0<b>ImListMigrationCompleted<\/b>\u00a0parameter instead of the\u00a0<b>\u200eSet-UMMailbox<\/b>\u00a0cmdlet. For example, run the following command:<\/p>\n<p>Set-Mailbox <a href=\"mailto:&lt;username&gt;@contoso.com\">&lt;username&gt;@contoso.com<\/a> -ImListMigrationCompleted $false<\/p>\n<p>&nbsp;<\/p>\n<p>Example:<\/p>\n<p>Set-Mailbox pdemmer@lifetouch.com\u00a0-ImListMigrationCompleted $false<\/p>\n<p>***Then attempt to migrate the user back to Exchange on-prem<\/p>\n<p><a href=\"http:\/\/microsoftgeek.com\/?attachment_id=2018#main\" rel=\"attachment wp-att-2018\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-2018\" src=\"http:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate-good.png\" alt=\"unabletomigrate-good\" width=\"988\" height=\"331\" srcset=\"https:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate-good.png 988w, https:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate-good-300x101.png 300w, https:\/\/microsoftgeek.com\/wp-content\/uploads\/2017\/01\/unabletomigrate-good-768x257.png 768w\" sizes=\"auto, (max-width: 988px) 100vw, 988px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>When you attempt to migrate an O365 user back to Exchange 2010 on-prem you may receive this error: &nbsp; &#8220;You shouldn&#8217;t migrate mailbox &#8216;Paul Demmer&#8217; to Exchange 2010 or an earlier version while the user&#8217;s Instant Messaging contact list is stored in Exchange. If you do, the user could permanently lose access to their Instant [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21,22,58,62,59],"tags":[],"class_list":["post-2016","post","type-post","status-publish","format-standard","hentry","category-exchange-2007","category-exchange-2010","category-exchange-2013","category-microsoft-exchange-server-2016","category-powershell"],"_links":{"self":[{"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=\/wp\/v2\/posts\/2016","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2016"}],"version-history":[{"count":6,"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=\/wp\/v2\/posts\/2016\/revisions"}],"predecessor-version":[{"id":2024,"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=\/wp\/v2\/posts\/2016\/revisions\/2024"}],"wp:attachment":[{"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2016"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2016"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microsoftgeek.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2016"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}