When composing a new message, after 2 minutes (or whatever is configured as autosave interval) a messagebox shows up: > Could not autosave message: Asked to use word wrapping, but not given wrapped plain text. Clicking "OK" shows the error message again a 2nd time. After dismissing this one, the error isn't shown until the next autosave cycle.
Also: when trying to send now a composed message I'm shown the error message: Could not compose message: Asked to use word wrapping, but not given wrapped plain text. Please report this bug. I didn't change anything in the KMail2 configuration since quite some time. I'm not sure, whether I sent a mail before since upgrading to 4.10 beta1 (4.9.80) from 4.9.3. I never saw any of the reported errors in 4.9.3.
Another discovery I just made: somehow, HTML is enabled now for new messages and when disabling HTML in the composer for new messages, I don't see any of the reported messages anymore.
fixed in master
*** Bug 311108 has been marked as a duplicate of this bug. ***