In Nintex Workflow 2013 when I try and configure some actions sometimes I get a information page that states "The website delcined to show this webpage". Under more information it goes on to say that the erro is HTTP 403 Forbidden. But it only happens sometimes and then if I close this window and configure other actions and then come back then I get the configuration screen, and other times I need to configure more other actions, before I can configure the erroring ones. Any assistance or guidance would be appreciated. We are using SP 2013 on prem and it has SP 1 and the May 2015 CU.