Posted in Flex forum but I guess this is really a Flash Builder question:
Since installing 4.5, I continue to get the message "preparing the design mode for...., i.e., taking a long time." Fine, so I use the checkbox to say stop asking me this and No I don't want to continue rendering, but it keeps asking every few seconds. It's almost worse than the old method where things just slowed down for a bit. Any advice on how to get it to stop asking?
Time taken is considered per file. And dont show me this option is applicable only for that file for that rendering. So if you close and open the file or if you open another big file, it may start the same process again.
So if you are working with pretty big files and if you are not planning to use design view. you can disable design mode by
Window -> Enable Desing Mode -Uncheck this option,