Observing a NoSuchMethodError warning in TransportSender.onAppError on APIM

[DaniduWijendra]

Description

We are observing the following warning on the APIM-4.5.0 environment under load or during backend degradation.

WARN {org.apache.synapse.core.axis2.TimeoutHandler} - Error occurred while processing callbacks java.lang.NoSuchMethodError: 'void org.apache.axis2.transport.TransportSender.onAppError(org.apache.axis2.context.MessageContext)'
	at org.apache.synapse.core.axis2.TimeoutHandler.processCallbacks(TimeoutHandler.java:289)
	at org.apache.synapse.core.axis2.TimeoutHandler.run(TimeoutHandler.java:99)
	at java.base/java.util.TimerThread.mainLoop(Timer.java:556)
	at java.base/java.util.TimerThread.run(Timer.java:506)

Steps to Reproduce

• Create an API with a POST request and configure a small endpoint timeout (5 seconds).
• Then send a large payload (~10MB) to the APIM server, and when the client is still uploading the payload, the 5-second backend timeout fires.

curl -k -v \
    -H "Authorization: Bearer <TOKEN>" \
    -H "Content-Type: application/octet-stream" \
    --limit-rate 100K \
    --data-binary @/tmp/bigpayload.bin \
    https://localhost:8243/slow/1.0/test

Version

4.5.0

Environment Details (with versions)

No response