Kmail crashes when typing a recipient email

Hi!
Is anyone else encountering this bug? I am at a loss how to help fix this - 
drkonqi does not catch this error.

https://bugs.kde.org/show_bug.cgi?id=505655

It affects me on all 3 of my systems, though they are all similar (arch linux, 
sway wayland, no plasma)

Cheers,
Bennett