Sometimes, your computer's print queue can get jammed up with old documents that failed to print for one reason or another, holding up the document you need right now.
Right-click on the printer icon in Windows' notification area, then choose Open All Printers to see a list of currently queued items. In macOS, you can see the queue from System Preferences > Printers & Scanners > Open Print Queue. Right-click any old items and clear them to get things chugging again.
Alternatively, in Windows, you can restart the print spooler, which will try to print those documents as if they were just added to the queue (so you don't have to clear them).
There are a few ways to do this, but the easiest is probably from the Command Prompt. Open the Start menu, search for "Command Prompt," right-click the option that appears, and choose Run As Administrator. Then paste in the following commands, pressing Enter after each one:
- net stop spooler
- del %systemroot%\System32\spool\PRINTERS\* /Q /F /S
- net start spooler
With any luck, this will bring your printer back to life and you'll get the document you've been waiting for.