If you are troubleshooting a specific build pipeline setup,To help narrow down the issue, please let me know: Your and Flex Builder/Eclipse version
A: The Flex 4.x SDK includes a "Flex 3 compatibility layer" (mx.core.FlexVersion). The installer checks for this patch by default. patch listing error flex 3
flex3.patch.ListingError: Failed to enumerate patches from [patch-directory] If you are troubleshooting a specific build pipeline
The fastest way to eliminate the error is to stop Flex from looking for patches it does not need. Open your Flash Builder or Eclipse IDE. To help narrow down the issue