Failed to deploy error returned when deploying solutions in the ArcGIS Enterprise portal

Description

When deploying a solution in the ArcGIS Enterprise portal, the following error message is returned:

Error:
<Solution> failed to deploy

This error prevents the successful deployment of the selected solution and its associated content.

Cause

This issue occurs when HTTPS is not enabled for the portal. HTTPS is required for secure communication during solution deployment.

Solution or Workaround

Enable HTTPS-only communication in the ArcGIS Enterprise portal. Refer to Portal for ArcGIS: Configure HTTPS for instructions. In Step 3, toggle on the Allow access to the portal through HTTPS only toggle button.