It is advisable to reset the browser.

Many crashes and bugs are caused by add-ons or changes to settings.Most of the problems will be fixed by changing the settings on the Firefox browser.Some of your lost information can be restored with a little extra work.

Step 1: You can visit your browser's page for problems.

The address bar is where you can enter about:support.There is a page titled Troubleshooting information.Clicking (usually in the top right) will take you to this page.There is a problem with the information.Click this link if this doesn't work.

Step 2: The browser needs to be refreshed by clicking the refresh button.

There is a button in the upper right.

Step 3: You should confirm.

Go back to the popup window and finish in the second window.All extensions, themes, and added search engines will be deleted.The settings will be restored to their original state.Button placement and preferences are included.Make sure you know where to find your downloaded files because your download history will be cleared.

Step 4: You should remove your old data.

The folder on your desktop is called "Old Firefox Data."The instructions below will help you restore some of your settings.

Step 5: In safe mode, open the browser.

Even if it won't open without crashing, this will let you reset it.Search your computer for a "Mozilla Firefox (Safe Mode)" shortcut if this doesn't work.Hold down the option while opening the browser.From Terminal, run /path/to/firefox.

Step 6: Hold the same key.

Hold down the same key if you see a list of profiles.If you have more than one profile, this will happen.

Step 7: You can refresh Firefox.

A popup with two items should appear before the browser window opens.To reset your settings and remove add-ons, select refresh firefox.This is not a temporary change.Start in Safe Mode if you want to see if that will solve the problem.If it does, try disabling add-ons.Start again in safe mode if it doesn't happen.

Step 8: If there is missing data, check for it.

This method can be used to restore search engines, website-specific settings, and download preferences, which do not usually cause bugs.Passwords, bookmarks, browsing history, and cookies should be restored automatically.You can still retrieve them using these instructions if they are missing.You can change your settings manually instead of using this method.If you want to recreate your old bugs, you should restore them from the backup.

Step 9: Open the page you are on.

Go to the address bar and enter about:support.Information about how to fix it.

Step 10: Your profile data can be opened.

The folder containing your profile data can be found by clicking a button near the top of the page.Depending on your system and browser version, look for the following words.

Step 11: Find old data.

There is a folder on your desktop that should hold your old data.If you can't find it, look for a folder called "Old Firefox Data" on your computer.You may need to show hidden files on Windows.

Step 12: It's time to quit the browser.

Before you change your profile settings, you should close Firefox.

Step 13: Take the files and put them into your profile.

Choose a file you want to transfer.For how to identify them, see below.Click the file to copy it.Go to your new folder.Click on any blank space in the folder to paste.Click the file to "right-click" on a Mac.If prompted, replace or destroy existing files.

Step 14: You can choose which files to transfer.

Since one of them could be responsible for the bug, it's best to keep as few files as possible.There are some files that should be transferred: search.json, your added search engines permissions.sqlite, and preferences for which websites are allowed to store cookies, open popup windows, etc.The preferences for handling downloaded files are listed in mimeTypes.rdf.If an error occurred during the reset, you don't need to restore them yourself.bookmarks and browsing history key3.db logins.json saved passwords form history.sqlite autofill information for online forms