Users of Apache Flex 4.10.0 (and later) have reported a problem when creating new Flex projects. The Application tag erroneously contains the attribute 'layout="absolute.'"
As described in FLEX-33636 in the Apache Flex bug base, a manual workaround is to use the editor to remove the erroneous attribute. However, to avoid requiring you to fix every new project, Adobe has created a patch to one of the JARs in Flash Builder. The JAR does not work with Flash Builder 4.6.