Thanks for this but you omitted the Office Version Number. Also, are you shown as the Belongs to: in the About Microsoft Word dialog or is something else shown there?
It also appears that there has been an attempt to modify the Ribbon... The default location of the Developer tab is at the extreme right end of the Ribbon, not immediately to the right of the Home tab. Note that in the Ribbon & Toolbar dialog the name of the Developer tab is followed by (Custom). You should find that the standard Developer tab is where it should be but may not be displayed due to the width of the window. Widen the window of=r click the » at the right of last tab shown on the Ribbon itself. Also, if you scroll down in the Ribbon & Toolbar dialog you should see Developer near the bottom of the list.
I suggest clicking the circled ellipsis at the bottom of the right column in Ribbon & Toolbar to Reset all customizations:
You may need to restart the program afterward.