Someone's MacBook doesn't connect to the internet.
At this point, connecting to different wifi networks and turning on and off the radio should be considered basic knowledge--if you'd like to argue to the contrary, please save us the trouble and acknowledge that you want to remove any semblance of security for users.
The proxy probably threw up a message describing that it was working properly, and that the requested content was blocked because of $reason.
Things were working as expected and designed, and the user tried to do something that was outside of that envelope. If the user wants to do more, the user should learn to do more.
Someone has embedded a YouTube video into a powerpoint presentation.
User did not understand the idea of remote content. User should be made aware of difference in remote content, possibly even later going on to use it to make smaller presentations where appropriate, or to guarantee operation in network-limited situations.
A user's laptop is running very slowly due to virus infection.
User acknowledged that they were aware of virus scanners, used file-sharing programs, and voluntarily did not take prophylactic measures.
A user complains of a computer not turning on, but it turns out the machine is on and the monitor is off.
User has apparently never used a television with a separate cable box, or a car with a radio, or a projector with a laptop. User now knows better, and can teach others!
A user cannot connect to the internet even after trying various software settings.
User did not understand function of all buttons on machine. User now understands function of wireless toggle on machine, can help others.
A user attempts to log in to a network site/computer.
User deliberately skips impatiently past diagnostic information sufficient to immediately ascertain source of issue and enable rectification.
User will go on to one day become stranded in traffic having ignored "low fuel" light in car.
A user has a new iPhone and is sad about loss of contacts.
User bought into frictionless ecosystem, and was not notified that the needful was already happening automatically--though pondering the question "what if my phone breaks?" would've prevented this.
(To be fair, this is outright poor software design.)
A user complains of not having internet access.
User never bothered to learn difference between shortcuts and files. User now knows difference, hopefully.
A user thinks they have a virus.
User does not notice telltale UI mismatch, and does not know machine well enough to catch that. User hopefully now knows better.