As for the message "Word could not create the work file. Check the temp environment variable" on Mac, please go to check whether you're using the latest version of the Word for Mac application first. If not, update it to the latest available, restart your Mac, and do a test to see the result.
Besides that, trying to move the Normal.dotm file from the Word for Mac application might troubleshoot this error message. Here are how to do:
1. Close the Word for Mac application.
2. Navigate to /Users/username(the account you use to log into the Mac) /Library/Group Containers/UBF8T346G9.Office/User Content/Templates to find the Normal.dotm file.
3. Move the file out of the Mac.
4. Open the Word for Mac application and a new default template Normal.dotm file should be created again in the Template folder.
5. Open the Word for Mac application again.