# Flex Error

**URL:** <https://forum.kirupa.com/t/flex-error/316479>\
**Category:** flash\
**Created:** [November 23, 2010, 3:18am UTC](https://forum.kirupa.com/t/flex-error/316479 "2010-11-23T03:18:35Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![zerdang](https://avatars.discourse-cdn.com/v4/letter/z/ecb155/32.png) [@zerdang](https://forum.kirupa.com/u/zerdang)\
**Post date:** [November 23, 2010, 3:18am UTC](https://forum.kirupa.com/t/flex-error/316479/1 "2010-11-23T03:18:35Z")

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Okay so I’m decently proficient at AS3 so when I tried switching to to Flash Builder (Flex) I got confused fast. I’m following this tutorial here  
[http://www.adobe.com/devnet/facebook/articles/flex\_fbgraph\_pt1.html](http://www.adobe.com/devnet/facebook/articles/flex_fbgraph_pt1.html)

I’m getting this error, which I believe is being caused by a problem with the app.xml file but I can’t really understand the error.

> Please correct the following problem in the app.xml file for this application.

invalid application descriptor: descriptor version does not match runtime version  
Launch command details: “C:\Program Files (x86)\Adobe\Adobe Flash Builder 4\sdks\4.0.0\bin\adl.exe” -runtime “C:\Program Files (x86)\Adobe\Adobe Flash Builder 4\sdks\4.0.0\runtimes\air\win” “D:\Documents\Documents (spencer)\AdobeScripts\FacebookUserStatusAIR\_1\bin-debug\FacebookUserStatusAIR-app.xml” “D:\Documents\Documents (spencer)\AdobeScripts\FacebookUserStatusAIR\_1\bin-debug”

Please help,  
zerdang