Unable to select conversation options using mouse

I am unable to select any conversation options using my mouse. The 'dialogue wheel' appears in the middle of the screen, and by mousing over options the text underlying the cursor becomes highlighted and the appropriate 'tone' icon appears in the middle of the wheel. However, clicking any of the options does nothing. I am only able to select a dialogue option by pressing the corresponding number key. This works to get through most plot-related conversations, however in particular 'in the field' conversations with companions and NPCs usually do not provide a number key keyed to a particular response, and so I am unable to progress any of these conversations - which is rather frustrating.

This issue has also been reported by others on Reddit and NeoGaf (see eg.  http://www.reddit.com/r/Games/comments/2mofqz/dragon_age_inquisition_bug_report/cm66l3c, http://67.227.255.239/forum/showpost.php?p=137947480&postcount=89 ) but the suggested fixes - Alt-Tabbing or right-clicking the screen - do not work for me.