I am 'almost' certain it relates to the file size being submitted as the message into the queue which is larger than normal.
From what I have read the default value comes from the Netty writeBufferHighWaterMark setting..........
writeBufferHighWaterMark . This parameter determines the high water mark of the Netty write buffer. If the number of bytes queued in the write buffer exceeds this value, Netty's channel will start to be not writable. The default value for this property is 131072 bytes (128KiB).
Is there a way I can change the default setting of 131,072 bytes within the Wildfly config (using standalone-full.xml) ?