Communication error codes on HP Laserjet printers are HP printer error 49. They can be difficult to troubleshoot at times, but these errors can range from temporary issues that clear up with a reboot to more serious issues that necessitate hardware replacement. The HP printer 49 service error occurs when the printer is unable to process a file that has been sent to it. Another error that affects your HP Printer is this one. To correct this mistake, you can try some general solutions. This error can be resolved by resolving network and connection problems, clearing pending printing jobs, and rebooting. The most common error on HP LaserJet pro 400 m401dn printers is 49 service errors. A bad order, corrupt data, invalid operations, firmware, formatter, or possibly accessories like an EIO card or memory, according to HP's printer service manual, can trigger the HP printer service error 49. Extra trays, duplexers, envelope feeders, and other items, according to some sources, may cause this error in some circumstances.