Extensions will not show in add-ons manager; Firefox start-up Java error

Question

When I click Tools --> Add-ons, the Add-ons Manager opens but no Extensions show in the Extensions tab.
I think the problem is related to a start-up error message I receive. Every time I open Firefox, an error message labeled "[JavaScript Application]" opens and displays the following:
aObj is undefined -- chooseValue((void 0),"name")@resource:///modules/XPIProvider.jsm:7032
()@resource:///modules/XPIProvider.jsm:7142
([object Object])@resource://yoono/yoonoLog.js:95
([object Object])@resource://yoono/yoonoLog.js:49
()@chrome://yoono/content/yoonoOverlay.js:176
()@chrome://yoono/content/yoonoOverlay.js:88
([object Array])@resource://yoono/yoonoService.js:949
safeCall((function (aAddonList) {try {for (var i = 0; i < aAddonList.length; i++) {_self.addOns[aAddonList[i].id] = aAddonList[i];if (YOONO_ID == aAddonList[i].id) {_self.setExtensionVersion(aAddonList[i].version);}}} catch (e) {CONSOLESERVICE.logStringMessage(e);}aCallBack();}),[object Array])@resource://gre/modules/AddonManager.jsm:50
([object Object])@resource://gre/modules/AddonManager.jsm:964
AOC_callNext()@resource://gre/modules/AddonManager.jsm:120
([object Array])@resource://gre/modules/AddonManager.jsm:959
PL_getAddonsByTypes(null,(function (aProviderAddons) {"use strict";addons = addons.concat(aProviderAddons);aCaller.callNext();}))@resource:///modules/PluginProvider.jsm:110
callProvider([object Object],"getAddonsByTypes",null,null,(function (aProviderAddons) {"use strict";addons = addons.concat(aProviderAddons);aCaller.callNext();}))@resource://gre/modules/AddonManager.jsm:78
([object Object],[object Object])@resource://gre/modules/AddonManager.jsm:957
AOC_callNext()@resource://gre/modules/AddonManager.jsm:126
([object Array])@resource://gre/modules/AddonManager.jsm:959
([object Array])@resource:///modules/XPIProvider.jsm:3094
completeAddon([object Object])@resource:///modules/XPIProvider.jsm:3895
getAddon([object Object])@resource://gre/modules/AddonRepository.jsm:504
("[email protected]",completeAddon)@resource://gre/modules/AddonRepository.jsm:536
([object Object])@resource:///modules/XPIProvider.jsm:3899
((function (aAddon) {"use strict";
function completeAddon(aRepositoryAddon) {aAddon._repositoryAddon = aRepositoryAddon;self.addons.push(aAddon);if (self.complete && self.addons.length == self.count) {self.callback(self.addons);}}
if ("getCachedAddonByID" in AddonRepository) {AddonRepository.getCachedAddonByID(aAddon.id, completeAddon);} else {completeAddon(null);}}),0,[object Array])@resource:///modules/XPIProvider.jsm:4796
(0)@resource:///modules/XPIProvider.jsm:4795
Any and all help would be much appreciated.
-Jason

Answer 1

The error means that an add-on called yoono is having problems communicating with a component made by Microsoft. I spoke to somebody with experience in working with the firefox coding, and he said that they're likely to be different issued and to see if yoono or another extension is causing the problems by opening firefox in safe mode. To open firefox in safe mode, [[Safe Mode|click here]]. If you can get to the addon manager there, I recommend you get rid of yoono