Navigate to Assets > Computers > Click into the device (Computer Details page)
Click "Remove Agent Upgrade Request"
To cancel multiple devices:
Login to the App Control Server
Launch SQL Server management Studio
Run one of the below queries:
--This will set all devices in "upgrade requested" or "upgrade scheduled" to "Not Requested"
update dbo.hostmain set upgrade_state = 16 WHERE deleted = '0' and upgrade_state in ('-2147483552','-2147483616')
--This will set the devices with host_id 1 or 2 to "Not Requested". Substitute these values with the desired host ids
update dbo.hostmain set upgrade_state = 16 WHERE host_id in ('1',',2')
To pause any "automatic" agent upgrades:
Login to the App Control Console
Navigate to System Configuration (gear icon) > Advanced Options tab
Click "Edit"
Under the "App Control Agent" section, change "Automatic Agent Upgrades" (Server 8.9 or Earlier) or "Allow Agent Upgrades" (Server 8.10 and Higher) from "Enabled" to "Disabled"
Note: This is only temporary and once this setting is enabled again, any devices that were previously scheduled will start trying to upgrade again.
Additional Information
If an agent is in the "Upgrade Scheduled" status it is generally too late to cancel the request. This means that the next check-in (every 30 seconds) the agent will attempt to upgrade. If the upgrade attempt were to fail, any subsequent attempts will stop once the upgrade request is cancelled.