Zendesk tickets fail to sync into cases in Salesforce

Issue Symptoms

I followed the instructions in Setting up Ticket Sync from Zendesk to Salesforce, but cases aren't being created or updated in Salesforce.

Resolution Steps

1. Open Admin Center and verify if the ticket sync is enabled.
2. Check if the (Salesforce Integration) Sync tickets to Salesforce trigger is active.
3. If ticket sync is enabled and the trigger is active, you should see an entry within the event view after creating or updating a ticket:
   
4. If you see the entry, turn on the Salesforce logs (instructions below). If you don't see this type of event in your tickets, review Setting up Ticket Sync from Zendesk to Salesforce.

To run the Salesforce logs

1. Log in to Salesforce using an Administrator account.
   Note: This does not need to be the same account used to authenticate from Zendesk to Salesforce. It can be any Salesforce Administrator.
2. Go to Setup > Environments > Logs > Debug Logs and create a new User Trace Flag with the details listed below.
   • Traced Entity Type: User.
   • Traced Entity Name: Select the user used to authenticate from Zendesk to Salesforce (This is the user used to login to Salesforce after clicking Connect in Central admin).
   • Start Date: Current Datetime.
   • End Date: Current Datetime plus 30 minutes.
   • Debug Level: You can use any existing debug level as long as it has at least “DEBUG” for Apex Code and System.
     
     
3. Click Save. You can now start debugging.
4. Create a ticket in Zendesk that meets the conditions of your trigger to push to Salesforce as a case.
5. Check the events of the ticket to be sure the trigger (Salesforce Integration) Sync tickets to Salesforce fired and you see Message pushed to target.
6. Switch back to Debug Logs in Salesforce and refresh the page.
7. Look for new entries with Request-type: API  and Operation: /services/data/v45,9/components/sobjects. Depending on the level of activity in your Zendesk, there may be multiple entries. Filter through the entries to identify the correct one.
8. Click View to open the log.
9. Look for Validation Fail or Required field missing messages, as these prevent the case from creating in Salesforce.

If there is no log available, this might indicate the following:

• The User Trace Flag had the incorrect user in the Trace entity name.
  To find the user who authenticated that connection to SFDC, go to Connected App Oauth Usage and click on the user count value.

• The trigger/target doesn't reach your SFDC instance. 
  To make sure they are connected properly, open a new incognito window browsing session and return to Admin Center. Once there, disconnect the Salesforce integration and then reconnect it. When reconnecting to log into SFDC as a System Administrator, insure full access to the necessary fields/objects.

If the above steps don't help to identify the cause of the issue, contact the Zendesk support team with the ID of the ticket created.