Looking at the situation I am suspecting that bad profile might causing an issue. in order to figure out whether issue is caused by bad profile you have to create a new profile and test situation by using new one. In case it resolved the issue then you should migrate all the data to new profile. It consist of following steps.
See that you have close Firefox completely.
Now you should click on start button and click on Run. In Run dialog box you have to click enter
‘firefox.exe –p’ without quotes and click on Ok button.
In case it does not work then you might need to mentioned full path of Firefox which I have mentioned below.
Also see that Firefox is not running in the background. It might cause did not opening of Profile Manage. You should close all instances of Firefox or simply reboot your computer.
On 32-bit Windows: "C:\Program Files\Mozilla Firefox\firefox.exe" –p
On 64-bit Windows: "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" –p
Now in order to create a new profile you click on Create Profile into Profile Manager.
After you have to click on Next and enter desire name . also you can mentioned desire location where you wanted to store your newly created profile. To do the same you have to click on Choose Folder.
Click on Finish button in order to create a new profile.