Seem to recollect that, when the B744 first flew pax, there was a problem with holding tanks indicating 'FULL' in error.
I heard that the high level sensors took exception to being paintballed by solid matter travelling at about 50 knots, indicated 'FULL' and shut down the section.
Engineers designed mod involving deflector plates or, as a non tech acquaintance referred to them, 'jobbie wheechers'.