"Unexpected end of JSON input" errors on ArcGIS Velocity for ArcGIS Enterprise home page

Error Message

Users may encounter errors on the ArcGIS Velocity for ArcGIS Enterprise Home page when certificate trust is not established between ArcGIS Velocity, Portal for ArcGIS, and ArcGIS Server. Common symptoms include the Home page displaying errors in the Resource Utilization section, failures when loading analytics or feeds, and feed creation workflows failing before the feed type selection page is displayed.

Users may observe errors such as:

• "Unexpected end of JSON input"
• "Failed to execute 'json' on 'Response': Unexpected end of JSON input"
• "There was an issue loading data for this page and the state of items or certain actions may be affected. Please contact Esri Technical Support if the problem persists."

Cause

ArcGIS Velocity requires secure HTTPS communication between its constituent components, such as the portal and ArcGIS Server.

Solution or Workaround

Ensure that certificate trust is established between ArcGIS Velocity, Portal for ArcGIS, and ArcGIS Server by completing the following:

1. Import the portal certificate into Velocity
2. Import the ArcGIS Server certificate into Velocity
3. Import Velocity’s certificate to the portal
4. Import Velocity’s certificate to ArcGIS Server

Note: 
If working in a disconnected environment without internet access, the Root CA and Intermediate CA certificates must also be imported manually to ensure the certificate chain is trusted by all components.