Unable to show all question on a single page

Hi Admin

Following recent update of both of this plugin and wordpress, I am unable to put all the question in a single page mode. I went into Watu dashboard, chekced "Show all questions on single page" and then saved it. But it does not change at all. In fact, the checked box goes unchecked. What to do and how to make an exam page in a single mode page.

Any help will be appreciated.