After resolving an Incident, end users are unable to open the resolution confirmation form. When clicking to work the task, the window opens and displays white, but it appears that the SD.Forms.IncidentManagement Workflow does not actually load. The URL appears to be build correctly, I am unsure what's causing the problem.
This defect only appears in ServiceDesk environments that are upgrades to 8.0 HF4. A fresh install of ServiceDesk 8.0 HF4 does not present the issue.
A version of the SD.Forms.IncidentManagement project was missing an entry point for the Affected User Confirmation model. Entry points just define which aspx landing page to use for which model. Since there was no mapping, it was just loading a blank page. Apparently, on upgrade, the DeploymentInfo.config file is not overwritten if present.
A workaround to the issue is to delete the DeploymentInfo.config file from the deployed project folder, and then open the SD.Forms.IncidentManagement Workflow and republish it.