Hi Zaba, the Nintex Workflow for Office 365 app should work regardless of the plan you are on. It'd be best to create a Ask Support ticket, and have our guys have a look at it for you.
Am I right in that your seeing that error within the SharePoint app store? From our experience that means that a pre-requisite feature we require and defined with the app is not available in your Tenant.
For NW365 we have one pre-requisite defined, support for the Workflow Manager. Can you confirm this is configured and working in your Office 365 tenant? (it should be), the best way would be to see if SharePoint Designer is working as expected.
Let us know how you go.
Thanks for setting me on the right track.
Workflow 2013 is not yet available in Office 365 Government E1, Office 365 Government E3, or Office 365 Government E4 plans.
Hey Guys Laura send me few minutes ago an Email with interesting information:
Thank you! We have a revelation!
We identified an issue within the Microsoft Office 365 infrastructure on Thursday that meant that new tenants provisioned by Microsoft did not include the workflow manager component. The issue manifests itself as the SharePoint App Store not allowing our Workflow app to be installed (as there is no workflow). Nintex Forms for Office 365 is unaffected.
Microsoft were alerted to this issue late yesterday and have made a fix to address this that will go live in a few hours for new tenants, over the coming days Microsoft will retrospectively fix the issue for any impacted customers.
Hopefully you can begin to use Nintex shortly!
Now we can hope, that MS fix the problem