Getting this error: Only ASCII supported in headers (perhaps SSL was used?)

Question

I am getting following error on using Jmeter recording controller:

ERROR - jmeter.protocol.http.proxy.Proxy: Problem with SSL certificate? Ensure browser is set to accept the JMeter proxy cert: Remote host closed connection during handshake 2013/10/29 14:02:08 ERROR - jmeter.protocol.http.proxy.Proxy: Problem with SSL certificate? Ensure browser is set to accept the JMeter proxy cert: Unrecognized SSL message, plaintext connection? 2013/10/29 14:02:40 ERROR - jmeter.protocol.http.proxy.Proxy: Not implemented (probably used https) java.lang.IllegalArgumentException: Only ASCII supported in headers (perhaps SSL was used?) at org.apache.jmeter.protocol.http.proxy.HttpRequestHdr.parse(HttpRequestHdr.java:155) at org.apache.jmeter.protocol.http.proxy.Proxy.run(Proxy.java:188)

Can someone help me debug this or explain me the root cause for this.

Answer 1

I believe that you can ignore these messages as they are likely to be caused by external URLs as per Recording HTTPS Traffic with JMeter guide

I suggest to retry your recording with monitoring of browser requests via HttpFox or Firebug Firefox plugins enabled to detect any external URLs which may cause these errors to appear. When you populate the list you can block these URLs via "URL Patterns to Exclude" field of JMeter HTTP Proxy server.