Unsupported language pack references found during site collection health check

Language packs let you create sites and site collections in multiple languages without requiring you to sign up for multiple instances of Microsoft SharePoint Online. After you run the pre-upgrade site collection health check, if the health check report shows a list of sites within your site collection for which the SharePoint Online 2013 language pack is not yet available, you must wait until the language pack becomes available. After the missing language pack is present, you can upgrade your site collection to SharePoint Online 2013 provided no other errors were found during the pre-upgrade health check.

Applies to:
SharePoint admin center, SharePoint Foundation 2013, SharePoint Online Enterprise (E1), SharePoint Online Enterprise (E3 & E4), SharePoint Online Midsized Business, SharePoint Online Small Business, SharePoint Server 2013 Enterprise, SharePoint Server 2013 Standard, SharePoint Foundation 2010 , SharePoint Server 2010