If you have extra language packs installed (very likely if you’re outside of the US!) then you need to first remove them before you can SP Exchange on your UM Server.
To find out the language packs installed you can use the Get-UMServer cmdlet:
Once you have ascertained what ones are installed you use setup to remove them
Command: setup.com /RemoveUMLanguagePack:en-GB
This will remove the en-GB language pack I had installed.
You can then Apply your Service Pack:
Once your SP has been installed correctly. You can re-install your language pack
Command: Setup.com /AddUmLanguagePack:<UmLanguagePackName> /s: d:\<languagepackfilelocation>
Don’t forget to re-select the language on your associated Dial Plans: