Spell Checker and Thesaurus Not Working

[RoryOF]

If the OO user profile has been correctly deleted, the new profile generated on next startup will normally pick the correct language.

[Bill]

Language selection problem as well

I don't recall ever seeing "Unknown" as a language in the Status bar of AOO and don't know how to reproduce that setting. is this a document created by some other program? Please upload a sample document so we can check the language setting on a working installation of AOO.

Your signature shows "Open Office 4.12", but there has never been an a version 4.12 of Apache OpenOffice. What version number is displayed when you click Help > About... ? Also, your first post mentions Windows 10, but the screen shots you have posted look like Windows 7, not Windows 10. The ribbon at the top of File Explorer in Windows 10 does not appear in your screen shots and the "Computer" icon in your screen shots is "This PC" in Windows 10. Which operating system are you using?