HelpUsing Flash Develop Instead of IntellIJ for AS3 FSOD

I'm trying to use flashdevelop for AS3 FSOD source because I don't want to just use intellij for one month and then have to buy it.

Anyways when I build the project in flashdevelop I get an error.
https://gyazo.com/644abc0044fb4c4351fa67e2c280bc9e

It's pretty self-explanatory it's just the fact that I can only open the project by opening that file, so everytime I try to build the project I get that error.
Help would be much appreciated.

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I'm just wondering how to build the project.

You can easily crack Intellij Idea Ultimate, just look for a key online. If you are using Mac OS, go to http://nmac.to/ⓘ for the crack.

what version of intellij is it? cause ik a key for intellij 14 but i don't got one for 15.