Kind of accidentally fell into the Windows10 programme, and have a few issues with it, particularly, its support for East Asian languages. I got your reply last night and started downloading the update, but it was slow, so I left it to continue as I went to bed. The new build surely looked different when I woke up. Anyway, before I tried what you said, the latest update asked me to "activate" for some reason, which I already did when I installed Build last week. I activated again regardless, however, Windows told me that it cannot complete the activation, and this was the error:.
Thank you for posting your question in Microsoft Community. From the problem description, it seems that you want to know how to install East Asian language pack on your computer. I can imagine the inconvenience you have experienced. I will try to help you in fixing the issue.
Language packs add additional display, help, and proofing tools to Office. You can install additional language accessory packs after installing Microsoft Office. If a language accessory pack is described as having partial localization, some parts of Office may still display in the language of your copy of Microsoft Office. If you're an administrator who has deployed a volume licensed version of Office to your users, you can download an ISO image of the language packs, language interface packs, and proofing tools from the Volume Licensing Service Center VLSC. If you're an administrator who has deployed a volume licensed version of Office to your users, you can deploy language packs by using the Office Deployment Tool.