Microsoft Words 2011 does not work with High Sierra

Microsoft Office 2011 is no longer supported (by Microsoft, and YMMV on High Sierra):

https://support.office.com/en-us/article/microsoft-office-support-for-macos-10-1 3-high-sierra-80bbd3cc-2412-4593-988a-1c5607b26b28

I'd strongly suggest you consider upgrading to Office 2016.

The last Office 2011 for Mac update from Microsoft was 14.7.7 in Oct. 2017. That is your best hope for a end-of-life product. Because Office 2011 for Mac was the last Office product to install components into OS X/macOS system areas, it might be a good idea to thoroughly uninstall, reinstall, and update to 14.7.7. Have your Office 2011 for Mac license key handy.

Microsoft Office 2011 for Mac (Word) Answers/Forum

I use Word from Office 2011 on High Sierra, it works fine. Uninstall it properly, reinstall and update it to the latest version (14.7.7)

Office 2011 works fine with HS although MS no longer supports. If your other Office Apps work fine (Excel, PPT, etc.) I suggest something else is wrong. You can try to reinstall Office 2011 which may fix the issue. You can also post in MS community site for assistance.

I have a new Apple Mac Pro computer that looks like a round black cyclinder and I updated to Mac High Sierra 10.13.9 and it works on my desktop with no problems and I purchased Microsoft Office:mac 2011 for home and student and it came with a hard DVD disk and I can only use it 5 times for any computer(s), but you have to have the product ID code in order to have it work on your computer(s) and without it you can't use the software to install in your computer. A few months ago I received a text that Microsoft Office:mac 2011 won't update my software anymore as of 2018. You mention that you have the Microsoft Office 2011 then use your hard disk again to install it into your Apple computer and put your Product ID Key to download your Microsoft Office 2011 again.