Migrate Site collection across versions with different language packs

Question

I have a task to recreate a SP2019 on-prem farm. Originally it was installed with Polish language, so both Central Adm and the site are in Polish. Now the idea is to have the English version installed, but separately install Polish language pack, so Central Adm will stay English but the main Site collection will be in Polish.

The question is about data migration: can I simply backup & restore this SPSite on this new farm installation, or will there be a version mismatch?

If this is off the table, what other possibility remains? Manual recreation? Is there some PS script which could help me with migrating data?

Answer 1

In most straightforward migration scenarios, if you have already installed the corresponding Language Pack for SharePoint 2019, you will not encounter a mismatch issue due to the Polish Language Pack.

In your case, You have to do the following:

• Prepare and Install SharePoint 2019 farm (English Version),
• After the installation is done, and before running the configuration wizard, download and install the Polish Language pack from Pakiety językowe dla programu SharePoint Server 2019. then run the configuration wizard.
• It's also recommended to download and install the latest Cumulative Updates (language-independent and a language-dependent) for SharePoint 2019 at (SharePoint 2019 update history) (download the CU for the previous month, not the current month)
• In SharePoint 2016 farm, make sure that there is no configuration/patching issue and your farm is up and running and recommended to be patched with the latest Updates (language-independent and a language-dependent) (SharePoint 2016 update history) (download the CU for the previous month, not the current month)
• Finally, start the migration process as mentioned at Backup and Restore SharePoint 2016 Web Application to another Farm and Upgrade to SharePoint Server 2019

Check also How to install New Update In SharePoint Farm | Patching SharePoint Farm Considerations

Answer 2

If what you want to do is change the language of Central Administration for a user, that is easy to do without re-installing. You can go the Central Administatration's Site settings -> Language settings -> choose English (or Polish) as the alternate language. The CA language will then be determined by the user's language in their profile, or if it is blank then by the browser language.