Clean Journal: 'The active theme is broken' – How do I fix it.

Updated to WordPress 4.7 yesterday and updated Clean Journal. However, the system now states: the active theme is broken. This means the site has reverted to running Twenty Sixteen theme. I have attempted to activate the Clean Journal but it won’t. I can’t delete it and start again either. See: http://www.europeancounselling.eu/ The theme appears NOT to be on the system but if I attempt to install it again it states that it is already installed. Then when I activate it, then it comes up with the note ‘active theme is broken’ again. So I can’t find it to delete it but if I attempt to reload it then it’s already there. I realise that this sounds silly! However, all the other various themes I have uploaded work. I’m using one.com ISP so I can I can easily install wordpress. We are about to launch a number of journals and now hope it won’t happen to the other ‘clean journal’ sites we have built. So not keen to update them. Regards Stephen