This can be caused by a problem with the file places.sqlite that stores the bookmarks and the history.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox

Problem continues after renaming places.sqlite and then starting Firefox again.

Where is this script, chrome://browser/content/places/browserPlacesViews.js:388, stored?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

• Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
• Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

In Firefox 4 you can use one of these to start in Safe mode:

• Help > Restart with Add-ons Disabled
• Hold down the Shift key while double clicking the Firefox desktop shortcut (Windows)

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Have done what is suggested above, but the problem persists. Do you know where this line of script resides?

You can see the content of that script if you paste the chrome URL in the location bar.

All those scripts are stored in a ZIP archive called omni.jar in the Firefox program folder.

• chrome://browser/content/places/browserPlacesViews.js

Unable to get into omni.jar, using my extraction tool in Power Pro 7. Attempt prompts "file is corrupted". Any suggestions?

When looking at the results shown when "chrome://browser/content/places/browserPlacesViews.js " entered in location field and executed, can find nothing that correlates with the error message, "Script: chrome://browser/content/places/browserPlacesViews.js:388". Line 388 is blank if the number is supposed to be the start of what has triggered the error message.

There is no need to access or modify that file. Did you use View > Page Source?

Line 388 is the last line with "return element;":

  _insertNewItemToPopup:
  function PVB__insertNewItemToPopup(aNewChild, aPopup, aBefore) {
    let element = this._createMenuItemForPlacesNode(aNewChild);

    if (aBefore) {
      aPopup.insertBefore(element, aBefore);
    }
    else {
      // Add the new element to the menu.  If there is static content at
      // the end of the menu, add the element before that.  Otherwise,
      // just add to the end.
      if (aPopup._endMarker != -1) {
        let lastElt = aPopup.childNodes[aPopup._endMarker];
        aPopup.insertBefore(element, lastElt);
      }
      else {
        aPopup.appendChild(element);
      }
    }

    if (aPopup._endMarker != -1)
      aPopup._endMarker++;

    return element; // line 388
  },

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

Using View>Page Source yields replay of this Q&A series. What's there does not help to find a remedy. Am I missing something in the suggestion?

In safe mode after disabling all add-ins and extensions the problem continues.

What is another approach to finding a solution to this "Unresponsive Script" problem?

Continue to have same problem after trying all of the suggested routines.

Any suggestions about next steps.