Perhaps I wasn’t clear. Here’s what to do.
1) Export a Quicktime reference or self-contained movie from FCP in your edit codec (DV, DVCPro50, DVCProHD, etc.).
2) Drag that to Compressor and choose an H.264 preset there (I’m not sure why you chose HD DVD. Do not use that. It doesn’t exist anymore.). Tell Compressor what size (in the Geometry tab of the Inspector) the image should be (320×240, 256 x 144, etc.).
3) Choose the data rate (in Video Settings in the Encoder tab of the Inspector) to use (500kbps, 700 kbps, etc.).
4) Encode your file. This will produce the file you want.
5) Now, change the extension .mov on the file made above to .flv and you should be good.
“Unable to connect to background process…” may mean Compressor is broken. Hopefully when you do the above you won’t get this message. But, if you do, this may help.
https://support.apple.com/kb/TS1888?viewlocale=en_US
John
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