My transparency disappeared

The transparency should have a white peel off strip! Without that the machine doesn't know it feed paper. Some transparency paper will have a backing sheet you peel off after printing. Check Staples for correct type.
This should be the edge that feeds first and should be on the on the non print side. if your not sure which side is printed on (face up / face down) open tray and draw an X on the top sheet.
then print anything and see if it prints over the X. If not then put peel off strip on the side (face up / face down) not printed on .

Hi
1st when using transparency paper U must set up the printer propreties to paper kind U use.
for now do the sim. 30 -1 to see hows sensor is detected bi touche

"generally" printers have a main tray and a manual feed tray, which is typically a fold down tray in the front of the printer. This manual tray allows the feed of envelopes, thicker paper, transparancies etc. including " custom sized paper" The printer is saying that your software identified that it "needs" custom paper instead of your
normal paper. Hope this helps.

this is an issue with the papper feed and pickup rollers if it is not taking the paper from draw you need to replace the pickup and feed rollers also check the paper feed clutch if no good replace as well
Also make sure also make sure the paper is being lifted up when you close the draw you should hear the tray lifting the paper up to the feed system

There are several possibilities. After you inspect for the Jam and close the drawer, does the copier come to ready? Have you checked the behind the doors on the right side. If the copier comes to ready and you press the start button does the copier jam right away. If so check the dial on the paper drawer and be sure its set to the right size paper. If its not the copier will jam, right away. It is important with a Canon to check all areas and open both the paper drawer and the right side doors when checking for jam, if the right sequence is not followed in checking for jams the jam may not clear. If still Jammed you might take some canned air open the right side door and blow out the paper feed area, a sensor may be blocked or dusty. If all else fails turn the machine off and un-plug it from the wall, let it set a few minutes and plug it in and try it again.

The rollers are either dirty , or most likely worn out and need to be replaced. They are not hard to replace, but humidity is not the problem, the condtion of the rollers is the problem. Try cleaning them with something like fantastic or formula 109, then clean again with alcohol.
They become slick and will not feed paper. You can google a business called The Parts Drop, they carry about everything for Xerox copiers.

Is there a paper selection wheel or bar in the tray?

Some of the older Canon models have a dial (usually in the lower right hand corner of the tray) or a slider bar (usually on the left hand side of the tray) when you open it. That has to be set properly or the machine has no idea what size paper is there.

I have a Dell 3010n myself, and a few times I did run into that "Load MPF" issue.
1.) Before printing a document, please check and see the properties. i.e. Kind/type of paper, which tray, or if printing envelopes or any other document than a regular 8 x11 paper. Putting all the tray and paper type selection on "Auto" can be very helpful.
2.) On the printer itself, there is a menu button where you can configure the type of paper, i.e. regular 20 llb. copy/print paper, glossy photopaper, thicker paper - after you place a fresh load on the paper tray and slide it in, usually it will ask you which type of paper you just loaded. Make sure it is the same settings as the document that you are trying to print: i.e. if document settings on computer was set to print on photopaper and you have regular paper on the tray, the printer will do a "Load MPF".
The paper sensor on it is amazingly (for a Dell, that is) sensitive and it can differentiate across a lot of paper types/thickness. If you have several computers and user across a network, and there are several paper-type settings done on the printer itself, this "Load MPF" issue will present itself more often.
In my case, it's simply because the person who recently changed the paper-type to glossy cover paper from some user who previously printed to a transparency forgot to revert MPF/Tray 1 to regular copy/print paper. Most cases, the printer setting on the PC has been left to print on to a transparency by default, so even if I stack the tray with copy paper to the hilt, it still will do "Load MPF".

When you close the doors does the message disappear? If so then the paper pickup roller is worn. Open the cassette remove all paper apart from one sheet. Spray a alcohol based cleaned on the leading edge of the paper. Try and do a copy this will issue a jam and also clean the pickup roller. repeat a few times then clean out the cassette and dry off place new paper in the cassette and try. Also there maybe a piece of paper behind the cassette. Remove cassette and reach in and remove paper lodged at back.

Thanks Jason

A jam sensor may be stuck or have something stuck on it, causing the machine to think it is jammed. These sensors are normally located where the paper feeds into the printer, and where the paper exits the printer. Try forcing a sheet of paper through the machine in the direction paper normally. feeds. This may free up the jam sensors.