Homebrew Character is not loading during encounter

I have a homebrew character I created for my campaign. The characters stat page comes up fine in the browser. The Encounter Builder allows me to 'see' and 'add' the character to the encounter and to save. But when I attempt to view the character in the encounter I get a blank 'an error has occurred' page. This character WAS working fine; I've had him created for over a year, used him on multiple occasions, and he worked fine. Then one day it just suddenly would not load in the encounter. My other homebrews are working and loading just fine. I've tried copying the character, and had the same issue with the copy. I've looked through the source code and attempted to correct any mistakes or typos I may have made - but nothing is working. Does anyone have any sort of fix for this?