Recently in one of our environments, we started getting the issue that all our workflows were getting stuck at “Waiting for resources”.
As usual first step was to check if Microsoft Dynamics 365 Asynchronous Processing Service is running it or not.
The service was disabled, so we enabled it. But still, it didn’t fix the issue.
Next thing we tried was as suggested in the below article
The value for AsyncSdkRootDomain was blank which we updated followed by a restart of the service. Still no luck.
Eventually, we came to know that Servers setting for the roles Full Server were in the disabled state inside the Deployment Manager for the organization.
The reason CRM was still working because these services (including IIS Web Site) were already manually started earlier, however, the status was still disabled for this setting within Deployment Manager. (These settings were done by the network team who were planning to create the replica of these machines, and they wanted to disable the applications and our CRM technical team was unaware of it.)
Enabling it fixed the issue for it.
Hope it helps..