It's been seen in some self-hosted customer environments that McAfee products, in particular McAfee Access Protection, can prevent importing of XML files (for example importing Update Sets) into the instance.
Release or Environment
All ServiceNow releases, however this applies only to self-hosted (on-prem / on-premise) environments
When an XML file is uploaded to the instance the node that the file is being uploaded on will create a temporary file named as a random hexadecimal string (e.g.0eb62e971b4b1810ebfd43f28d4bcb38) in the directory /glide/nodes/<node name>/webapps/glide/itil/WEB-INF/update/customer/uploads/
It will then rename this file to be the filename of the XML file that was uploaded (e.g. update_set_2020-09-17.xml), and then shortly after it will delete this temporary file so that the /glide/nodes/<node name>/webapps/glide/itil/WEB-INF/update/customer/uploads/ directory is empty again.
It's been seen in some customer environments that McAfee products such as McAfee Access Protection block this create, then rename, then delete operation. The XML import then fails silently.
ServiceNow is able to help troubleshoot issues like this, but once it's been narrowed down to a different vendor's product there isn't much we can do further. Customers affected by this issue should contact McAfee's support team to troubleshoot further with them.