Other people (including me) had the same problem with the FPOS, see here and here.
PS: Btw, instead of inserting images of your terminal, you could copy and paste the output into your posts here. There is even the possibility to display these as code (the </> icon in the menu or the shortcut Strg+Shift+C or four empty spaces at the beginning of the line). This would save storage space on the server (and probably be faster). 
Didn’t you forget the flash command in here? Like:
$ fastboot flash boot out/target/product/FP2/boot.img