Thanks, bgermann.
I found a post about a broken cforms administration page (since WordPress 4.2 related to URL encoding the / in the request parameter) which I am also experiencing (using cforms 14.6.) The suggested fix in the cforms code does not work for me for some reason.
I would like to update to the latest version of cforms but I am afraid I will lose my forms. What do you recommend when upgrading/
(Sorry for asking but I’m completely new to WordPress.)