the question about FileTransferProxy

I don't understand FileTransferProxy used for？if i stop this , It may affect the openfire work?because my openfire often logs below：

org.jivesoftware.openfire.filetransfer.proxy.ProxyConnectionManager - Error processing file transfer proxy connection

java.io.IOException: Only SOCKS5 supported

        at org.jivesoftware.openfire.filetransfer.proxy.ProxyConnectionManager.processConn ection(ProxyConnectionManager.java:158)

        at org.jivesoftware.openfire.filetransfer.proxy.ProxyConnectionManager.access$200( ProxyConnectionManager.java:57)

        at org.jivesoftware.openfire.filetransfer.proxy.ProxyConnectionManager$1$1.run(Pro xyConnectionManager.java:127)

        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)

        at java.util.concurrent.FutureTask.run(FutureTask.java:266)

        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

        at java.lang.Thread.run(Thread.java:745)