Starting Firefox first time is kinda problematic aka funky… because window flashes and disappears. From Task Manager I can see the process is running. Sometimes program launches on second attempt, sometimes if process is killed. Thanks to Add/Remove Software app (via Launch button), Firefox starts rock solid on first go. Is there a solution to this annoying behavior?
Have you tried launching it from the terminal, and see if any error is printed there?
Also from terminal Firefox flashes/flickers and ends up as a process without graphic interface.
Reinstall seem to fix the issue.
Next time will dive in debugging section of arch linux wiki