Anyone on here know their way around a 567?

Was having issues with my monitor saying end gate was open when it wasn’t. Read to put shims in the gate latch, after doing that and turning the monitor back on it’s now showing the code E1 02, which states bale size sensor unhooked. I can’t seem to find online where that sensor is, plan to go back out to the field in the morning and look it over before I head to work. Any help would be appreciated

When run Deere balers the tailgate indicator usually meant had a bunch of chaff built up so locking pins weren't fully closed . Would see it time to time on second crop where had a lot of fines . Would open end gate and clean chaff from around lock and be good

I had that problem with my old 535, so that was first thing I checked on this one but they were unobstructed