Fall back to previous version

Hi,Since the last updateI have been encoutering several problems with the Page Builder plugin. It gets no customizations (colors, images, etc) the wigets that I add in my rows are not workingproperly, they are changing positions after every update,my changes are not saved (of course I update every change that i make).
Since I must deliver my sites to my clients as soon as possible, and this malfunction gets me behind in temrs of deadlines, please intruct me on how to fall back in the previous version of site builder, until you fix the bugs.