SAP Connector Troubleshooting

This page contains common troubleshooting suggestions for the SAP Connector.

Checking Log Files

Mule stores log files (on a per application basis) in the $MULE_HOME\logs directory:

  • mule.log - default Mule log file.

  • mule-app-YOUR_APP_NAME.log - per application log file.

Enabling JCo Trace

JCo Trace can be enabled from outside Mule and accepts the following Java startup environment properties:

  • -Djco.trace_level=N (where 0 <= N <= 10, with 10 = most detailed trace)

  • -Djco.trace_path=<PATH> (optional)

To enable traces at the connector level, perform the following steps:

  1. Set the attribute jcoTrace to true or provide the extended JCo property jco.client.trace or jco.server.trace with value 1.

  2. Provide a value for -Djco.trace_level=N at Mule startup. JCo offers trace levels from 0 to 10. The amount of traced data increases with the chosen trace level. Each trace level also contains all the trace data from the lower trace levels. For details about the traced data please see the table below. If you are using a high JCo trace level with lots of JCo calls and transferred content, please make sure that enough disk space is available. Default value is 0.

    Trace Level AS Java Severity Level JCo 3 Trace Content



    No trace.



    JCo version and runtime environment info.
    JCo internal errors and exceptions without application errors.



    JCo warning messages (for example, non-ABAP system exceptions).



    JCo information messages (for example, ABAP exceptions).



    RFC calls and important public API calls.



    Important internal middleware calls.
    Codepage information.



    Connection attributes.
    ASCII content data (first 1000 chars of structures / first 5 rows of tables).



    RFC metadata (name, type, offset, length, import/export options) and additional Hex values for content data.



    Full content data dump (no character or row limits).
    Caller stack trace information (for example, for getClient() - identifies application).



    No additional information (reserved for future use).



    No additional information (reserved for future use).

  3. Optionally, you can provide a value for -Djco.trace_path=<PATH>. This is supposed to be the complete path to an existing directory where trace files will be stored, but there are other special values can be applied:

    • stdout - JCo trace information is sent to standard output stream.

    • stderr - JCo trace information is sent to standard error stream.

If -Djco.trace_path is not set, then trace files will be stored in the working directory. For Mule standalone, this is usually the $MULE_HOME/bin folder.

Common Errors

JCo Missing Libraries


This exception typically occurs when testing the connection or trying to deploy the Mule application without loading one or more of the required SAP JCo dependencies:

  • Missing JCo native library

    java.lang.ExceptionInInitializerError: JCo initialization failed with java.lang.UnsatisfiedLinkError: no sapjco3 in java.library.path
    SAP Error JCo Native Library
  • Missing JCo JAR

    java.lang.NoClassDefFoundError: com/sap/conn/jco/JCoTraceListener
    SAP Error JCo JAR
  • Missing IDoc JAR

    java.lang.NoClassDefFoundError: com/sap/conn/idoc/IDocMetaDataUnavailableException
    SAP Error IDoc JAR


To add these libraries to your project, click the Add File button in the Global Element Properties window, where you see the listed libraries with the red exclamation mark, and browse to and select the appropriate file. The SAP libraries will be automatically added to the project classpath.

You can see the libraries in the project build path by right-clicking the project in the Package Explorer, navigating to Build Path > Configure Build Path.

JCo Classloader Conflicts

java.lang.ExceptionInInitializerError: JCo initialization failed with java.lang.UnsatisfiedLinkError: Native Library /home/mule/sap-errors/lib/jco/libsapjco3.so already loaded in another classloader


When you load the native library from the Global Configuration, a copy of the file is placed inside $YOUR_APP/src/main/app/lib, but the "original" one is not removed. Hence, you will get this exception if it shares the same directory as the JCo jar files when testing the connection or deploying your app.

SAP Error JCo Classloader Folder


  • Straightforward approach: just remove the duplicate native library file from the directory where your JCo jars live.

SAP Error JCo Classloader Fix
  • Best-practice approach: configure the environment variable LD_LIBRARY_PATH to hold the dynamic link library and share it across multiple applications deployed within the same Mule runtime server.

For further information, take a look at Share JCo Dependencies Among Multiple Applications.

JCo Version Conflicts

java.lang.ExceptionInInitializerError: Native library sapjco3 is too old. Found library System-defined path to libsapjco3.so has version "720.612", but required is at least version "720.713".


The most frequent cause is employing different versions of the native library and the JCo jars.


Verify the following:

  • JCo is compatible with the underlying JVM. The 64-bit JCo is required on a JVM that runs in 64-bit mode, and the 32-bit JCo on a JVM running in 32-bit mode.

  • On Microsoft® Windows®, JCo requires the Microsoft Visual Studio 2005 C/C++ runtime libraries.

  • The sapjco.jar, and sapjco3.dll or sapjco3.so or sapjco3.jnilib files must be from the same JCo package.

    To check the versions of the JCo libraries that you are using, do one of the following:

    • From the UI (Windows):

      1. Navigate to the directory where the sapjco3.jar file is located.

      2. Right-click the sapjco3.jar file.

      3. Select Open With from the context menu.

      4. Click Java 2 Platform Standard Edition binary.

      5. A SAP Java Connector (JCo) dialog will pop-up displaying the information about the JCo and Java versions used.

    • From a console:

      1. Open a terminal console.

      2. Navigate to the directory where the sapjco3.jar file is located.

      3. Execute the command java -jar sapjco3.jar -version.

      4. A SAP Java Connector (JCo) dialog will pop up displaying the information about the JCo and Java versions used.


JCo Renaming Conflicts

java.lang.ExceptionInInitializerError: Illegal JCo archive "sapjco3-3.0.11.jar". It is not allowed to rename or repackage the original archive "sapjco3.jar"


Since the release of JCo 3.0.11, you cannot change the names of any of the SAP JCo library files from their original names, as they won’t be recognized by JCo.


If you are using Maven, the suggested workaround is to configure the maven-dependency-plugin with the attribute <stripVersion>true</stripVersion>. This way, all version numbers of the dependent libs will be stripped when copying the JCo artifacts.

Further information is available externally at the Apache Maven Dependency Plugin.

Transformer Needs a Valid Endpoint

java.lang.IllegalStateException: This transformer needs a valid endpoint


The outputXml attribute of the SAP endpoint has been set to false, thus disabling the implicit use of the sap:object-to-xml transformer.

Transformer Error


  • Option A: change the value of outputXml to true.

  • Option B: add a sap:object-to-xml transformer to the flow.

Transformer Fix

Message Not a SAP Object

org.mule.api.transport.DispatchException: Message is not a SAP object, it is of type "byte[]". Check the transformer for this Connector "SapConnector". Failed to route event via endpoint: SapOutboundEndpoint{endpointUri=sap://function, connector=SapConnector
,  name='endpoint.sap.function', mep=ONE_WAY, properties={evaluateFunctionResponse=false, bapiTransaction=false, functionName=BAPI_MATERIAL_AVAILABILITY, rfcType=srfc, outputXml=true}, transactionConfig=Transaction{factory=null, action=INDIFFERENT, timeout=0}, deleteUnacceptedMessages=false, initialState=started, responseTimeout=10000, endpointEncoding=UTF-8, disableTransportTransformer=false}. Message payload is of type: byte[]


As clearly stated in the exception message, the endpoint is expecting a SAP Object with the input parameters to execute a BAPI or IDoc but none has been provided or the object is malformed.


Create a SAP object that represents the call to the BAPI or IDoc. There are two options here:

  1. Create a XML that represents a SAP Object with the BAPI call.

  2. Provide a XML definition and use the input inside that definition to create the actual SAP call.

IDoc Metadata Unavailable

RfcException: [mc-vmware|a_rfc] message: (3) IDOC_ERROR_METADATA_UNAVAILABLE: The meta data for the IDoc type "??????????????????????????å å" with extension "  ORDSAPB6L B60CL          ???" is unavailable.
    Return code: RFC_FAILURE(1)
    error group: 104


The RFC destination should support Unicode.


Configure Unicode support in your SAP instance using transaction SM59.

Cannot Join a Transaction

SAP Connector Cannot Join Transaction of Type [org.mule.TransactionClass]

The action of type [srfc|trfc|qrfc] will be stateless, because SAP Transport doesn’t support Multi Transactions for the moment.

Missing TID Handler

[10-11 08:02:26] ERROR SapJcoServerDefaultListener [JCoServerThread-1]: Exception occurred on idoc_send connection 3-|sapgw00|idoc_send: check TID fault: No transaction handler is installed. Unable to process tRFC/qRFC requests.
RfcException: [mule.local|MULESOFT_IDOC_SEND_TEST]
    message: check TID fault: No transaction handler is installed. Unable to process tRFC/qRFC requests.
    Return code: RFC_FAILURE(1)
    error group: 104
Exception raised by myhost.com.ar|MULESOFT_IDOC_SEND_TEST
    at com.sap.conn.jco.rt.MiddlewareJavaRfc$JavaRfcServer.playbackTRfc(MiddlewareJavaRfc.java:2625)
    at com.sap.conn.jco.rt.MiddlewareJavaRfc$JavaRfcServer.handletRfcRequest(MiddlewareJavaRfc.java:2546)
    at com.sap.conn.jco.rt.MiddlewareJavaRfc$JavaRfcServer.listen(MiddlewareJavaRfc.java:2367)
    at com.sap.conn.jco.rt.DefaultServerWorker.dispatch(DefaultServerWorker.java:284)
    at com.sap.conn.jco.rt.DefaultServerWorker.loop(DefaultServerWorker.java:369)
    at com.sap.conn.jco.rt.DefaultServerWorker.run(DefaultServerWorker.java:245)
    at java.lang.Thread.run(Thread.java:680)


No TID handler has been defined.


Set the rfcType to trfc or qrfc in the <sap:inbound-endpoint />.

Parameter Not Supported

Root Exception stack trace:
RfcException: [null]
message: Parameter 'type' not supported: 'f'
error group: 101

at com.sap.conn.rfc.api.RfcOptions.checkParameters(RfcOptions.java:182)
at com.sap.conn.jco.rt.MiddlewareJavaRfc$JavaRfcClient.connect(MiddlewareJavaRfc.java:1328)
at com.sap.conn.jco.rt.ClientConnection.connect(ClientConnection.java:731)
+ 3 more (set debug level logging or '-Dmule.verbose.exceptions=true' for everything)


SAP extended properties (configured in a Map bean or as endpoint address parameters) should have valid names. If you provide an invalid property name you will get an error message similar to the above.

In this example, JCo libraries are reporting that the parameter with name type is not valid.


Provide a valid property name. The complete list of extended properties can be found here.

Multiple JCo Servers Running

ERROR 2012-07-05 10:11:30,525 [WrapperListener_start_runner] com.mulesoft.mule.transport.sap.SapMessageReceiver: Error connecting to server
com.sap.conn.jco.JCoException: (101) JCO_ERROR_CONFIGURATION: Server configuration for sapavalara-1.0-SNAPSHOT-gettax is already used for a running server
at com.sap.conn.jco.rt.StandaloneServerFactory.update(StandaloneServerFactory.java:358)
at com.sap.conn.jco.rt.StandaloneServerFactory.getServerInstance(StandaloneServerFactory.java:176)
at com.sap.conn.jco.server.JCoServerFactory.getServer(JCoServerFactory.java:74)
at com.mulesoft.mule.transport.sap.jco3.SapJcoRfcServer.initialise(SapJcoRfcServer.java:46)
at com.mulesoft.mule.transport.sap.jco3.SapJcoServerFactory.create(SapJcoServerFactory.java:60)
at com.mulesoft.mule.transport.sap.SapMessageReceiver.doConnect(SapMessageReceiver.java:56)
at org.mule.transport.AbstractTransportMessageHandler.connect(AbstractTransportMessageHandler.java:218)
at org.mule.transport.AbstractConnector.registerListener(AbstractConnector.java:1254)


There cannot be two or more JCo servers with the same set of configuration parameters, even if they have different configuration names.


The server group key (that determines the uniqueness of a JCo server connection) is given by the following attributes:

  • jco.server.gwhost

  • jco.server.gwserv

  • jco.server.progid

So, you can start two servers in the same Mule instance (JCo keeps this information in a Singleton class) as long as they have different values for gwhost, gwserv and progid.

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