Mozilla Firefox web browser is perhaps the most downloaded third party web browser and works across a number of platforms – Windows, Linux, Mac, Android and iOS. Apart from the features built inside the Firefox browser, you can enhance it using a number of add-ons as well as some of the plugins. While the add-ons are usually installed from the Mozilla add-ons website, while the plugins are installed through their dedicated software installers or through Firefox itself. But if your Firefox profile’s plugins database files become corrupted, you won’t be able to install any new more plugins the Firefox.
You can fix this problem easily by resetting the plugins database that is located in the Firefox profile folder. Here is how:
- Launch Firefox browser, type about:support in the address bar and press Enter.
- On the Troubleshooting Information page, scroll down and click on the Open Folder button.
- This will open the Firefox profile folder in Windows File Explorer. Before proceeding any further close all the Firefox windows.
- Locate the file named pluginreg.dat from this folder or rename it to pluginreg.dat.bak.
- Restart Firefox and enter about:plugins in the address bar to view all the installed plugins.
- Now you can install new plugins in Firefox, for example the Adobe Shockwave Flash.
This method works because the pluginreg.dat file becomes corrupt and new entries cannot be made to anymore. By deleting this file, Firefox is forced to recreate this file all over again and the problem disappears. But if one of the files has become corrupt, then you have to check your hard drive for any problems. You can use the command chkdsk /F C: to check the C: partition for errors. You can repeat this command for all the partitions to see of the file system has some problems in your Windows computer.