SAX Parser Exceprtion

When I run my application the following error will occur sometimes, but only sometimes. Can you explain why it occurs only occasionally and what the solution for this is?

The error message is:

03-13 14:38:18.055: WARN/System.err(1866): org.xml.sax.SAXParseException: expected: '>' actual: '?' (position:END_TAG </Curre>@137:35 in java.io.StringReader@438e0ef0) 
03-13 14:38:18.064: WARN/System.err(1866):     at org.apache.harmony.xml.parsers.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:151)
03-13 14:38:18.074: WARN/System.err(1866):     at com.fitzengineering.teslaworldnet.interfacelayer.ParseXMLString.convertPeoples(ParseXMLString.java:484)
03-13 14:38:18.074: WARN/System.err(1866):     at com.fitzengineering.teslaworldnet.presentationlayer.People.onCreate(People.java:91)
03-13 14:38:18.074: WARN/System.err(1866):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
03-13 14:38:18.084: WARN/System.err(1866):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2231)
03-13 14:38:18.095: WARN/System.err(1866):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2284)
03-13 14:38:18.104: WARN/System.err(1866):     at android.app.ActivityThread.access$1800(ActivityThread.java:112)03-13 14:38:18.104: WARN/System.err(1866): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692)
03-13 14:38:18.114: WARN/System.err(1866):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-13 14:38:18.124: WARN/System.err(1866):     at android.os.Looper.loop(Looper.java:123)
03-13 14:38:18.134: WARN开发者_如何学运维/System.err(1866):     at android.app.ActivityThread.main(ActivityThread.java:3948)
03-13 14:38:18.134: WARN/System.err(1866):     at java.lang.reflect.Method.invokeNative(Native Method)
03-13 14:38:18.144: WARN/System.err(1866):     at java.lang.reflect.Method.invoke(Method.java:521)
03-13 14:38:18.144: WARN/System.err(1866):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
03-13 14:38:18.154: WARN/System.err(1866):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
03-13 14:38:18.154: WARN/System.err(1866): 

Thanks in advance