Make Firefox and Firefox Development Edition running together (64-Bit)

After upgrading my Firefox and Firefox Development Edition to 64-Bit, i was no longer able to start them at the same time. Trying this will result in a message like „Firefox is already running but not responding“.

Today i found the solution on the Mozilla support page – but only inside the google cache, because the topic is no longer available for some reason, so i publish it this way again.

The solution is to use different profiles for each Firefox. To do this you have to create a second profile and add a custom shortcut and link directly to the second profile via the -P (= Profile) parameter.

Here we go (just for Windows – see links beyond to get help for other systems):

1. Create a second Firefox profile
   1. Press WIN+R and type: „firefox -ProfileManager“ – hit enter.
   2. Create a new Profile (i create a new profile for the DEV Edition), as i can say it’s not nessesary to choose a folder manually, simply click next.
   3. Create a shortcut to the FF Dev EXE (which is typicaly located under „C:\Program Files\Mozilla Firefox“ or „C:\Program Files\Firefox Developer Edition“, which one you have to choose depends on the Firefox edition you want to use your new profile with)
   4. In the target field add the -P parameter, example: „C:\Program Files\Firefox Developer Edition\firefox.exe“ -P „tf@webks.de“ (in this case including all quotes!)

For more detailed informations see:

https://developer.mozilla.org/en-US/docs/Mozilla/Command_Line_Options