Originally Posted by meme
I noticed you had several dictionaries in the hunspell_dictionaries directory that appear to already be included in Sigil - so I was curious why you loaded them?
I was getting desperate and trying anything to solve the problem.
The blank lines arose when for some reason the preferences box would not let me enter new words, but instead inserted blanks at each try and made the cursor jump up and down the list trying to match the word. You need to find out how it can get into that state, which is how the mess started.
I will report it if I see it again, but kiwidude's requests notwithstanding, I hope to never see it again!