When EUA has successfully completed, it installs an MSI that creates an EUA_AUTO1000 registry key under:
 
This installation is to prevent the EUA ePolicy Orchestrator (ePO) deployment task from running again when McAfee Agent / Trellix Agent is updated. EUA creates a Microsoft Windows scheduled task, EUA_Uninstall and EUA_reg_delete, to uninstall the MSI and remove this registry key. The task is scheduled to run two days after EUA finishes with the "Run this task as soon as possible after a scheduled start is missed" option enabled. It also triggers an expiration date 30 days after EUA finishes.

If you execute EUA before the MSI is uninstalled, it exits when it detects the EUA_AUTO1000 key.

If you manually remove this key from the registry and then execute EUA, EUA completes but exits with -1 instead of 0. The reason is that the EUA MSI is still installed and it can't be installed again to create the EUA_AUTO1000 key.

To successfully execute EUA again, perform one of the following workarounds.

Workaround 1
Run the EUA_Uninstall and EUA_reg_delete scheduled task from the Windows Task Scheduler.

Workaround 2
In ePO, create a Client Task to remove EUA:

1. From the ePO menu, select Client Task Catalog.
2. From the Client Task Types list on the left side, select McAfee Agent.
3. Click New Task at the top.
4. Select Product Deployment from the drop-down list and click OK.
5. Name the Client Task.
6. From the Products and Components drop-down list, select Endpoint Upgrade Assistant.
7. From the Action drop-down list, choose Remove.
8. Click Save.
9. Run the client task on the target systems using Run Client Task Now or by assigning the Client Task. For more information about Client Tasks, see the ePolicy Orchestrator Product Guide for your version.
   
   For product documents, go to the Product Documentation portal.