As you know Workflow Manager is the vital part of SharePoint 2013/2016/2019 Deployment. If it was not properly configured then you are in for a tough time for 2013/2016/2019 workflows. Troubleshooting is not an easy task in this scenario. Let's summarize some tips for the proper Installation and Configuration of the Workflow Manager. 

  1. Make sure to run the Workflow Manager with a domain account.
  2. Log in with an account which has DB creator and Security admin on the SQL Server and local admin on the WFM server.
  3. Run As account should be in proper format i.e domain\username or
  4. The account running the Register-SPWorkflowService command should have access to the WorkFlow Databases.
  5. Add the Workflow Manager Certs into SharePoint Trust.
  6. Make sure the Workflow client install is on all server in the farm (if workflow manager not installed on them).
  7. Make sure Bypass proxy server for local addresses option is enabled.
  8. Make sure App Management Service and Subscription Settings Service are set, as Workflow Manager has some hidden dependencies on these services. These services are required when you try to publish SharePoint 2013 Designer Workflow then this error will happen: "The workflow files were saved but cannot be run".
  9. Install the Service Bus 1.1 Hotfix before registering the workflow proxy. This fix is required for .NET 4.6+.
  10. Make sure firewall is not blocking the following Ports:
    1. WorkFlow Manager Ports 12290 & 12291
    2. Service Bus Ports:
      1. HTTPS 9355
      2. TCP 9354
      3. Message Broker Port 9356
      4. Internal Communication Port Range 9000 - 9004
      5. AMQP 5671-5672
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