I have a workflow that worked until this past Friday 2014/10/24. Now whenever the workflow attempts to access _api/Web/SiteUserInfoList/Items
I get an Access Denied error. I had another user start the workflow and it results in the same thing. I went to the URL that was giving the error in the workflow and I was able to load it just fine.
I am using SharePoint online. Is there maybe an update that they did that I need to work around or fix? Some of my users have access to the permissions, could they have messed something up? I am admin and have full access to the site, and couldn't find anything different with permissions.