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Downloaded 9.0.1 firefox will not open

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  • 1 has this problem
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  • Last reply by Vivek

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Downloaded Version 9.0.1 to replace 7.0.1 and when I attempted to open Firefox, the following error message came up:

This application has failed to start because MOZCRT19.dll was not found. Re-installing application may fix problem.

Re-installed - no help, Microsoft internet search for fix - no help

Downloaded Version 9.0.1 to replace 7.0.1 and when I attempted to open Firefox, the following error message came up: This application has failed to start because MOZCRT19.dll was not found. Re-installing application may fix problem. Re-installed - no help, Microsoft internet search for fix - no help

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Hi,

I think MOZCRT19.dll is not used anymore and it doesn't come with the latest Firefox installer. Please try uninstalling Firefox and delete the Firefox installation folder Computer > ?\Program Files\Mozilla Firefox or Computer > ?\Program Files (x86)\Mozilla Firefox before installing the new one. When uninstalling do not enable the option to delete profile and preferences. You may also want to take a backup of your Firefox Profile Folder & Files which is separate from the installation folder and stores bookmarks, passwords etc.

https://www.mozilla.org/en-US/firefox/new/

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Useful links:

All about Tools > Options

Going beyond Tools > Options - about:config

about:config Entries

Page Info Tools (Alt + T) > Page Info, Right-click > View Page Info

Keyboard Shortcuts

Viewing Video without Plugins

Firefox Profile Folder & Files

Firefox Commands

Basic Troubleshooting

After Upgrading

Safe Mode

Problematic Extensions

Troubleshooting Extensions and Themes

Troubleshooting Plugins

Testing Plugins

Modified by Vivek