Webservice client with exception due to preload

I’ve implemented a webservice with Yii. The webservice is working normally (passing objects ect). However when at the main.php configuration file, the following line is added

'preload'=>array('log'),

the client of the web service get’s a fatal exception like

[size="1"] Fatal error: Uncaught SoapFault exception: [Client] looks like we got no XML document in[/size]…

[size=“1”] Stack trace:#0 [internal function]: SoapClient->__call(‘register’, Array)#[/size]…

Can anyone explain this for me?

maybe you should disable debug

maybe you have db-profiling enabled

however, the output is not a valid xml-document

Use file logging for web service actions

/Tommy