I forgot to fill the water tank of the Nespresso machine. I’ve done this 3 or 4 times in the past, and it always means that due to an airlock water won’t flow when I next use it after refilling. In the past it has involved a lot of fiddling and about half an hour wasted, but this time after nearly 2 hours of trying various things I still had not solved the problem. Finally fixed it by putting a zip locked plastic bag into the top of the water container, creating a seal and then pushing on the top to pressurise the water, at which point the pump primed and water started flowing. I decided I deserved a drink after that, so rewarded myself with a glass of wine, not a cup of coffee!