Welcome to the HP Community Forum.
Your printer's Support Website:
HP LaserJet Pro 400 color Printer M451dn
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Preparation
Before you download new files or make any changes to your computer, always create a Restore Point:
- Close running programs, browsers, and games
- Create a Restore Point
Restore Point XP OR Create a Restore Point – Win7 OR Create a restore point Win8
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Suggested Solution
If you have not done so, you might consider the applying the Firmware Update:
HP LaserJet Pro Series Firmware Update Utility
Note the following from "Fixes":
HP LaserJet Pro 300-400 color MFP M375-M475 Series Firmware Enhancements and Fix List 20150126
- Fixed a 49 error when printing certain documents.
- Fixed a potential vulnerability issue (CVE-2014-3566) also known as the POODLE SSL v3.0 vulnerability.
- Fixes an issue the printer may not print where fonts are greater than 72pt.
- Fixes an issue that could cause loss of network connectivity on wireless networks with multiple access points having the same SSID.
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