It was removed from 5.5.1
Is i back in CS6!!!
That is just a warning. It will never stop you from exporting. It's just making a suggestion to set those TextFields to use device fonts for max compatibility but that's all. You can entirely disregard that error.
The problem is not on export.
Selecting some complex library items, I can wait up to 30 seconds before flash gets responsive again, and tenths of those messages appear in output window.
Makes the library unusable in many cases.
In your original post you said nothing about selecting library items and did in fact in your topic and 3rd paragraph talk about exporting.
Try saving your file down to the lowest version of flash you can. File->Save-As->Bottom drop-down.. From CS5 you should be able to get it down to CS4. Then try opening the CS4 doc in CS5.5.
the bug refers to flash CS5.5, and it has then completely been fixed in the first upgrade.
Now, in CS6, export works fine. The bug that slows unbearably the library is back though.
Yes you are right this topic is about the export crash bug in cs 5.5.
I think we can consider this topic closed, I have posted a bug report for cs6.