The file m2550pul.dll belongs to the Konica Minolta PostScript CPSUI module (FUMGNU1_DLL). This file is part of a printer driver from Konica Minolta. A driver is a program that makes your computer work with a specific piece of hardware. Windows has a number of built-in drivers, but some hardware requires users to install new drivers to make it work properly.
An error with this file indicates that you have a driver problem with your printer. If you have time and the original software that came with your printer, you can attempt to reinstall the driver. If you just want it fixed, you should try cleaning your registry.
ZookaWare PC Cleaner will scan your system for errors and fix them for you. Instead of finding old software to reinstall, or risking disabling your computer by editing the registry yourself, trust ZookaWare PC Cleaner to clean your registry and get your system back up to speed.