The “Paper Mismatch” or “Paper Size Mismatch” error can occur when the paper, envelopes or other media loaded in the printer tray or feeder is a different size than the paper selected in the printer settings and is a safeguard programed into your printer to prevent ink or toner from being wasted.Some printer models have an option that allows you to ignore the error and continue printing regardless of the mismatch. If you choose to ignore the error, the margins on your printout might not be proportional to the edges of the paper. hp printers troubleshooting
Step 1: Adjust the paper size settingCheck the paper size setting to make sure it matches the paper you want to print.1. In the program you want to print from, click File, and then click Print.2. Make sure your printer is in the Name or Printers drop-down list box, and then click Properties, Printer Properties or Preferences, depending on the program options.3. Click the Paper/Quality tab.4. Click Advanced, if necessary, and then click Paper Size.

1. Select the paper size that matches the size and type of paper loaded in the printer tray, and then click OK. If there are no matching paper sizes, select the size from the list that is closest to the size of the paper loaded in the tray.6. Click OK, and then try to print.If the error message persists, continue to the next step.Step 2: Check the paper source settingRemove and reload the paper in the input trays, and then check the paper source setting.1. Remove all the paper from all the printer input trays.2. Reload the paper, and then adjust the paper width guides so they gently rest against the edge of the paper stack.3. In the program you want to print from, click File, and then click Print.4. Make sure your printer is in the Name or Printers drop-down list box, and then click Properties, Printer Properties or Preferences, depending on the program options.5. Click the Paper/Quality tab, and then click Paper Source to select the correct tray.6. Click OK, and then try to print.If the error message persists, continue to the next step.Step 3: Reset the printerReset the printer to clear any hardware issues or error states.1. With the printer turned on, disconnect the power cord from the rear of the printer.2. Unplug the power cord from the wall outlet.3. Wait a minimum of 60 seconds.4. Plug the power cord back into the wall outlet.5. Reconnect the power cord to the rear of the printer.6. Turn on the printer.7. Wait until the printer is idle and silent before you continue.
   HP printer’s users commonly face the problem when their printer just refuses to print anything. This problem can arise due to various reasons ranging from connectivity issues to faulty configurations or drivers. If you are facing any such problem, the following troubleshooting guide will help you get rid of your printer won’t print problem.
2. Go for basic troubleshootingIn case your HP printer stops working, the first thing to do id to check the status of the connection between your printer and your computer. Make sure that all your devices are connected properly to one another, and the network or the cable that you use to connect these devices is working.You can also take a chance at restarting your HP printer. Turn it off for a couple of minutes, unplug the cord and leave it for a few minutes. Now, plug the cord to the printer and power it on. See if your problem is resolved.
3. Update or reinstall the required driversMore often than not, printers show problem because of faulty drivers. You may be required to update or reinstall these drivers to fix your printing issue. hp printer troubleshooting guide
4. Set your printer to defaultWhen you try to print something, your computer will automatically assign that printing task to the default printer unless you manually choose to do it with some other printer. So, your HP printer won’t be able to print anything if you have neither set it as your default printer nor select it as the printer to print. reference link = hp printer troubleshooting guide