Panosonic KX FP342 (fax)

Open the cabnet and check the film whether it is empty or not placed well. TheMacGyver suggested you the right thing. You can re-roll the the film, but it is very hard and needs perfection. Buy the new one and placed it properly.

The film cartridge can be purchased at almost any office supply store like Staples, Office Max, Office Depot, online and even Ebay.

IF there is film still left, make sure that the tension of the film is tight where there isn't any slack. If there is too much slack, or you are at the end of the roll, then you will get that message on your machine. One thing you can try is to roll the film backwards. There is a supply roll, and a take up roll. Just take the cartridge out and spin the roll the opposite way for about 5 feet or so. Then place the cartridge back in and see if it works. If it works then all you need to do is buy a new cartridge.
Hope this helps.
Good luck