Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
The printer is presumably either
1. not sensing paper in the tray. (Note: 'the tray' may mean 'the selected tray'. This can refer, on occasion and when the message is non-specific as to *which* tray has no paper in it, to a different tray than the one you suppose, not having paper in it.)
2. defective control circuitry that does not accurately report what the printer is sensing.
When you see the next 'no paper' message, try putting at least one sheet in *every* tray and every possible paper-feed location: that includes the manual feed slot, if there is one on your model.
If that clears the error message (and esp. if one of those sheets gets fed into the printer and printed upon!) then your printer has no problem, it's just settings. Those settings would be those for Paper Tray, or Paper Source, and the problem might be that 'Auto' is set for the paper tray or paper source to feed blank paper from.
If that does not clear the error message, then you have a different problem, and possibly one with your printer.
Let me know how it goes, and I will advise you further.