Add an editing or authoring language or set language preferences in Office

How to Install and Use Microsoft Office 2016 Arabic Language Pack (32-bit)

Follow the on-screen instructions, agree to the terms, and click "Install."

Go to File > Account and click Update Options > Update Now . Sometimes updating Office automatically resolves deployment discrepancies. Alternatively, use the Online Repair tool via the Windows Control Panel to reset your Office configuration. Missing Proofing Tools (Spell Check Not Working)

Do you use a version or a Click-to-Run version of Office 2016?