Are you able to start Firefox in its Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

(Yes, Reset is an option there, but it could be useful to try Safe Mode first if you can.)

If Firefox is not running, you can try holding down the Shift key when starting Firefox to get to the Safe Mode/Reset dialog.

I tried putting it in safe mode but it didn't fix anything.

In case a global plugin is blocking the search box:

Firefox 30 switched many plugins from "Always Activate" to "Ask to Activate". The purpose of this change was to require your permission for untrusted sites to use plugins. However, some plugins that affect the user interface and/or operate globally on all pages do not work well with this setting and unpredictable UI breakage can result.

Could you review your plugins as follows:

Open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Then I suggest:

• For in-page, player-type plugins like Flash, Silverlight, or Java, no changes are needed
• For global plugins like fingerprint readers or security software, switch to either:
  • "Always Activate" if you use this plugin on a regular basis
  • "Never Activate" if this plugin is not important or very rarely used

This might not take effect immediately in the current window, but should work in new windows, or after you exit and restart Firefox.

Does that help at all?

Firefox only crashes when you try to access the Troubleshooting Information page, or other parts of the interface? Hmm this might not be as helpful as usual, but maybe:

When Firefox crashes, it usually records information about what was happening at that moment -- you see the Mozilla Crash Reporter. You can submit that data to Mozilla and share it with forum volunteers to see whether it points to the solution. Please check the support article "Firefox Crashes" (especially the last section) for steps to get those crash IDs, and then post some of the recent ones here.