spellcheck results squeezed into status bar, complaining about words that (according to 'find') are not in the document, not highlighting words or moving to misspelled words, not suggesting correct spellings - spellchecking without adding formatting characters was one of the main reasons I downloaded Kate, without it there's little that Kate does that Wordpad won't do for me.
Possibly related: configuring the spellcheck in Kate's settings panel and hitting "apply" produces the message "No backend for for spell checking".
Hmm... what language are you trying to to use for spelling?
Did the downloading of the dictionary succeed? You can download additional dictionaries from: https://cgit.freedesktop.org/libreoffice/dictionaries/plain/<language code>/<language code>.aff https://cgit.freedesktop.org/libreoffice/dictionaries/plain/<language code>/<language code>.dic You need both the .aff and .dic file Then place them in bin/data/hunspell/
American English. I can confirm that the two language files are where they are supposed to be.
We think that is fixed nowadays, could you try a current version from our homepage and retry? If that really still happens for you, please reopen.