All SP workflows in the SharePoint site, suddenly stopped working!
When I tried to republish a workflow, I got this error: “Unable to properly communicate with the workflow service”
Verify that all the following Windows NT services are started:
b. Service Bus Backend
c. Service Bus Gateway
1. Open IIS Manager.
2. Under Application Pools, right-click WorkflowMgmtPool, and select Recycle… from the context menu.
In IIS find out the WorkflowHostUri
Run the below PowerShell command as an admin:
Register-SPWorkflowService -SPSite "http://localhost/" -WorkflowHostUri "http://localhost:12291/" -AllowOAuthHttp –Force
Please see https://msdn.microsoft.com/library/azure/jj193529(v=azure.10).aspx#WorkflowManagementService