Our team came across a problem when building the Nintex workflow in first time. We are using 30 day trial O365 account and 30 day trial Nintex app. We have tried in several browsers (Chrome , IE) and different site collections. Please find below steps to recreate the issue.
Steps to recreate the error.
01.Create basic Nintex list workflow.
02.Save the workflow.
During the build it prompts below error.