wiki

Firefox seems to be slow, reset it:

Open a new tab 
Navigate to about:support  in your address bar to bring up the Troubleshooting Information page.
Click on Reset

For information:

You will loose Extensions and themes, website-specific preferences, search engines, download history, DOM storage, security settings, download actions, plugin settings, toolbar customizations, user styles and social features will be removed. 

Open new Tab
Navigate to about:config
Accept security warning
Change "extensions.blocklist.enabled" to "false" (Simply double-click on that)

To save your password in a flat file you can use a script in python:

https://github.com/christophetd/firepwned

python firepwned.py --profile "C:\Users\Christophe\AppData\Roaming\Mozilla\Firefox\Profiles\xxxxxx.default"