White box appears behind Mac OSX Word

There are newer versions of Word available. The current one is 2016.

Do a backup, using either Time Machine or a cloning program, to ensure files/data can be recovered. Two backups are better than one.

Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.

Isolating an issue by using another user account

If the problem is still there, try booting into the Safe Mode using your normal account. Disconnect all peripherals except those needed for the test. Shut down the computer and then power it back up after waiting 10 seconds. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. When you reboot normally, the initial reboot may be slower than normal. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart by using the application un-installer or by using the developer’s uninstall instructions. For each disable/delete, you will need to restart if you don't do them all at once.

Safe Mode - About El Capitan also Sierra

Safe Mode Startup – El Capitan. also Sierra

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor. Please use copy and paste as screen shots can be hard to read. On the screen with Options, please open Options and check the bottom 2 boxes before running. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown.

Etrecheck – System Information

My parent's had this issue on their Mac. I noticed they had malware on there as well, as soon as I downloaded Malwarebytes and removed the malware, that seemed to have resolved it for them-- they've since gotten a new Mac, and updated to Office 2016, so I'm not sure if that completely resolved it, or was just a temporary fix.

Same issue here. I tried a clean re-installation of Office 2008, but Microsoft seems to have shut down the validation web page, so I think we're stuck with whatever Sierra imported from El Capitan. I have a bigger screen, and I can see all of my desktop icons, so it's less of a pain for me.

Workaround would be to make an alias of the "Desktop" folder (in your user folder), and put it where you can see it.

Office for Mac 2008 is no longer supported; you have to buy (ugh!) the Office 365 subscription (pay, pay, and pay, forever) or buy outright Office 2016 for Mac ($150 retail for the "Home and Student" version.) You can check eBay for Office for Mac 2011, which is still supported.