# File opens in CS3 but not in CS4 (unexpected file format)

**URL:** <https://forum.kirupa.com/t/file-opens-in-cs3-but-not-in-cs4-unexpected-file-format/300679>\
**Category:** flash\
**Created:** [November 25, 2009, 1:16pm UTC](https://forum.kirupa.com/t/file-opens-in-cs3-but-not-in-cs4-unexpected-file-format/300679 "2009-11-25T13:16:11Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![enridp](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@enridp](https://forum.kirupa.com/u/enridp)\
**Post date:** [November 25, 2009, 1:16pm UTC](https://forum.kirupa.com/t/file-opens-in-cs3-but-not-in-cs4-unexpected-file-format/300679/1 "2009-11-25T13:16:11Z")

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Hello! I’ve seen this with many .fla  
I can’t open them in CS4, but they works fine in CS3 (so what I’m doing is opening them in CS3, save again, and then they works in CS4).  
I think that is because the .fla are saved with Flash 8, but I don’t know why CS4 can’t open those .fla and CS3 yes.  
Is this a bug?

Thanks !  
E.-