User Error, from WikiPedia:
The phrase User Error or USR error, is a technical term asserting that any
issues caused are the fault of the user. It is a euphemistic way to suggest that the device is neither flawed nor poorly designed for
human usage, but the user does not understand how to make it
work properly. It is generally used by computer techs to imply a lack of computer savvy, but can additionally be used in other contexts.
A number of IT professionals believe user error to be by far and away the most common cause of reported computer
issues in the workplace. Common examples include attempting to enter a
case-sensitive password with
caps-lock on, clicking
Yes on message boxes without reading them properly and deleting important files, forgetting to plug an ethernet cable into their laptop's network card when in the office, allowing sessions to timeout when using a web application and erroneous data entry.