What happens when all this technology crashes big time?

Major Solar Flare?
We already see institutions systems crashing regularly.
So much inconvenience. Imagine a major bank losing its system for a week.
Supermarket systems crash, tills not working, they have to shut down until the fault is found and rectified.
Major power outages, people who rely on machines to keep them alive.
There is so much potential for world wide mayhem because of technology.