When trying to answer certain HTML mails, the composer shows the following error message twice, and also when trying to send the mail:

Could not compose (or autosave) message: Asked to use word wrapping, but not given wrapped plain text.

This effectively makes answering those mails impossible when using Word Wrap. As a workaround one can disable this from the Options menu of the composer.

Reproducible: Always

Steps to Reproduce:
1. Select an HTML mail in the message list and press Reply.
2. The composer opens and displays the above error message twice.
3. Try to send or queue the message. The error message is again shown twice, the composer stays open and the mail is not sent. 
Actual Results:  
The above mentioned error message is shown.

Expected Results:  
No error messages, and the mail being correctly sent.

This doesn't seem to happen for plain text mails or when the quoted text of the answered mail is rendered in plain text in the composer. Only HTML mails are affected.