To fix the previous error, go to /ApacheFlex/source/flex-sdk/frameworks/build.xml and search for playerglobal-setswfversion. Then add additional version checks for the Flash Player you want to use,
<condition property="playerglobal.swfversion" value="25">
<equals arg1="${playerglobal.version}" arg2="14.0" />
</condition>
Going forward, it might be more future proof to get the version number, 14,
15, 16, etc and add 11 to it to get the SWF version.
