Fix Nssutil3.dll Not Found Errors

What is nssutil3.dll?

The nssutil3.dll module belongs to Network Security Services from the Mozilla Foundation.

The nssutil3.dll file is known to exist in following file sizes:

  • 87,368 bytes
  • 41,984 bytes
  • 81,920 bytes
  • 87,552 bytes

Removal of the nssutil3.dll file may prevent you from loading the Firefox browser.

Nssutil3.dll issues with BitDefender and Bullgaurd

Certain protective software, such as BitDefender and Bullgaurd falsely report nssutil3.dll as a trojan and delete the file. As a result, users who have these protective tools installed on their computers may receive the following error, when they try to open the Firefox browser:

“This application failed to start because nssutil3.dll was not found. Re-installing the application may fix this problem.”

The error is not resolved when you download and install the nssutil3.dll file, as BitDefender or Bullgaurd will immediately delete the nssutil3.dll file again.


To repair the error, update your protective tool with the latest virus definitions and reinstall Firefox. Try to open the Firefox browser again and see if the error is fixed.

If the error persists after updating the protective tool, make an exception for BitDefender or Bullgaurd to ignore the Firefox folder when performing a scan, and then reinstall Firefox.

If the above steps fail to resolve the issue, you may want to switch to a different protective tool or Internet browser.

Besides issues with certain protective software, other common reasons for a nssutil3.dll missing or nssutil3.dll not found error are:

  • Missing nssutil3.dll
  • Malware infection
  • Registry issues

Depending on the cause of the nssutil3.dll error, you may perform the following steps to fix the nssutil3.dll missing or not found error:

Download nssutil3.dll from the Internet

If the nssutil3.dll error is occurring due to a missing nssutil3.dll file, download and install the nssutil3.dll file from a reliable and trustworthy online free DLL directory.

Perform a virus/malware scan

Malware, such as a virus and trojans deliberately corrupt DLLs by deleting or altering the codes embedded in them. If a malware has corrupted the copy of the nssutil3.dll file on your system, an nssutil3.dll error may be generated every time an application, such as Firefox, tries to access the infected file.

To fix nssutil3.dll errors occurring due to malware infection, scan and clean your entire system, using advanced security tools, such as STOPzilla Antivirus and Spyware Cease. Also, to prevent future nssutil3.dll errors due to malware infection, regularly update your security tools with the latest virus definitions and security updates.

Run a Registry Scan

You may also receive recurring nssutil3.dll errors if the entries of this file in the registry are invalid, corrupt, or removed. Scan your registry regularly using reliable registry cleaning software, such as RegServe, to ensure that the registry stores only valid and correct information. You can use RegServe to perform custom scans to identify and rectify DLL errors, such as nssutil3.dll errors.