The Apache Flex SDK installer caches patch listings from https://archive.apache.org/dist/flex/. If your local cache is corrupted, the installer cannot parse the patch index.

The latest Apache releases have backported the Flex 3 patch listing as a built-in module. Simply install with:

java -jar apache-flex-sdk-installer-4.16.1.jar --accept-license --include-flex3-patches

There are three primary drivers for these errors in a Flex 3 environment:

If you are seeing a “Patch Listing Error” while trying to build, run, or license a Flex 3 application — especially one using FlexNet Publisher (FNP, formerly FlexLM) — it typically indicates a mismatch or corruption in patch tracking data.

Q: Does this error affect Flash Player or AIR applications? A: Yes. Any Flex 3 application running on modern Flash Player runtimes (32+) may require patch listing alignment.

Q: I don't even use Flex 3. Why am I seeing this error? A: The Flex 4.x SDK includes a "Flex 3 compatibility layer" (mx.core.FlexVersion). The installer checks for this patch by default.

Q: Can I disable patch listing entirely? A: Yes, but not recommended. Set env.FLEX_PATCH_LIST=ignore before compilation:

export FLEX_PATCH_LIST=ignore && ant main

Q: Is there a community fix? A: Yes. The Apache Flex JIRA issue FLEX-35500 has a community-built shell script that automatically remaps all dead patch URLs to the Apache archive.

To avoid repeating the "Patch Listing Error Flex 3" nightmare, follow these best practices:

The "patch listing error flex 3" is one of many signs that maintenance on Flex 3 has become unsustainable. Consider:

Navigate to the patch repository:

find /usr/sap/trans/EPS/in -name "*.xml" -exec xmllint --noout {} \;

If xmllint reports errors, your patch listing is corrupted.