Thank you so much! I did indeed have a font called "Blank" on my system, which I do not recall installing. However, after deleting this font, Opera is now working perfectly.
If anyone else has this problem investigate C:\Windows\Fonts and delete any "Blank" font (mine was called Blank Blank in the Font Manager).
If it says the font is in use (keep in mind I use Windows 8.1):
Right click the blank font and select 'properties'
Take note of the file name
del "C:\Windows\Fonts\font-name.ttf"
Open CMD and type the above command BUT DO NOT RUN (your path might differ from mine)
Open task manager, close any running instance of Opera and explorer.exe (your Windows UI will disappear, but we'll get it back shortly)
DO NOT CLOSE TASK MANAGER
Run the command in CMD
After the Font is deleted, go back to task manager
Click 'File' then 'Run New Task'
Type "explorer" (without quotes) and click ok
Start Opera