apache axis2 websevice doesnt work on the online server!

I've developed a web service using apache axis2 and eclipse which consists of these methods:

String getStatus()
Stock[] getStocksList(String username, String password)
Collection<AdviserMsg> getMsgsFromTseTmc()
AdviserMsg[] getMsgList(String username, String password)

The services work fine on the local server but when I upload them on the server this weird problem comes up, the first method (开发者_开发问答getStatus()) which only returns a string works fine but other methods don't! I get this result in response:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
- <soapenv:Body>
- <soapenv:Fault>
  <faultcode>soapenv:Server</faultcode> 
  <faultstring>Exception occurred while trying to invoke service method getMsgList</faultstring> 
  <detail /> 
  </soapenv:Fault>
  </soapenv:Body>
  </soapenv:Envelope>

Necessary to mention that this exact project worked fine a few days ago and all of a sudden it decided to make me hit my head against all of the possible walls in the office. and also I uploaded the project on another server too, and the result was the same.

Any ideas?