What is causing this error, and how do I fix it?

```
WebClient webClient = new WebClient();
HtmlPage page = webClient.getPage("http://stackoverflow.com");

```

Error message

> 
> May 25, 2013 10:34:12 AM com.gargoylesoftware.htmlunit.IncorrectnessListenerImpl notify
>  WARNING: Obsolete content type encountered: 'text/javascript'.
>  May 25, 2013 10:34:13 AM com.gargoylesoftware.htmlunit.javascript.StrictErrorReporter runtimeError
>  SEVERE: runtimeError: message=[The data necessary to complete this operation is not yet available.] sourceName=[http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js] line=[2] lineSource=[null] lineOffset=[0]
>  May 25, 2013 10:34:15 AM com.gargoylesoftware.htmlunit.IncorrectnessListenerImpl notify
>  WARNING: Obsolete content type encountered: 'text/javascript'.
>  May 25, 2013 10:34:16 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:3230] Error in style rule. (Invalid token "!". Was expecting one of: , , , "inherit", , , , , , , , , , , , , , , , , , , , , , , , , , "}", ";", "/", "-".)
>  May 25, 2013 10:34:16 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler warning
>  WARNING: CSS warning: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:3230] Ignoring the following declarations in this rule.
>  May 25, 2013 10:34:16 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:6341] Error in style rule. (Invalid token "!". Was expecting one of: , , , "inherit", , , , , , , , , , , , , , , , , , , , , , , , , , "}", ";", "/", "-".)
>  May 25, 2013 10:34:16 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler warning
>  WARNING: CSS warning: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:6341] Ignoring the following declarations in this rule.
>  May 25, 2013 10:34:16 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:14777] Error in style rule. (Invalid token "!". Was expecting one of: , , , "inherit", , , , , , , , , , , , , , , , , , , , , , , , , , "}", ";", "/", "-".)
>  May 25, 2013 10:34:16 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler warning
>  WARNING: CSS warning: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:14777] Ignoring the following declarations in this rule.
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:31657] Error in style rule. (Invalid token "!". Was expecting one of: , , , "inherit", , , , , , , , , , , , , , , , , , , , , , , , , , "}", ";", "/", "-".)
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler warning
>  WARNING: CSS warning: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:31657] Ignoring the following declarations in this rule.
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:73253] Error in style rule. (Invalid token ":". Was expecting one of: , , , "inherit", , , , , , , , , , , , , , , , , , , , , , , , , , "}", ";", "/", "-".)
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler warning
>  WARNING: CSS warning: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:73253] Ignoring the following declarations in this rule.
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:112886] Error in expression. (Invalid token "#ffffff". Was expecting one of: , , , , , , , "-", "=", ")".)
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler error
>  WARNING: CSS error: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:112928] Error in style rule. (Invalid token "background". Was expecting one of: , "}", ";".)
>  May 25, 2013 10:34:17 AM com.gargoylesoftware.htmlunit.DefaultCssErrorHandler warning
>  WARNING: CSS warning: 'cdn.sstatic.net/stackoverflow/all.css?v=1748204ca390' [1:112928] Ignoring the following declarations in this rule.
>  May 25, 2013 10:34:19 AM com.gargoylesoftware.htmlunit.javascript.host.ActiveXObject jsConstructor
>  WARNING: Automation server can't create object for 'ShockwaveFlash.ShockwaveFlash.7'.
>  May 25, 2013 10:34:19 AM com.gargoylesoftware.htmlunit.javascript.StrictErrorReporter runtimeError
>  SEVERE: runtimeError: message=[Automation server can't create object for 'ShockwaveFlash.ShockwaveFlash.7'.] sourceName=[http://www.google-analytics.com/ga.js] line=[25] lineSource=[null] lineOffset=[0]
>  May 25, 2013 10:34:19 AM com.gargoylesoftware.htmlunit.javascript.host.ActiveXObject jsConstructor
>  WARNING: Automation server can't create object for 'ShockwaveFlash.ShockwaveFlash.6'.
>  May 25, 2013 10:34:19 AM com.gargoylesoftware.htmlunit.javascript.StrictErrorReporter runtimeError
>  SEVERE: runtimeError: message=[Automation server can't create object for 'ShockwaveFlash.ShockwaveFlash.6'.] sourceName=[http://www.google-analytics.com/ga.js] line=[25] lineSource=[null] lineOffset=[0]
>  May 25, 2013 10:34:19 AM com.gargoylesoftware.htmlunit.javascript.host.ActiveXObject jsConstructor
>  WARNING: Automation server can't create object for 'ShockwaveFlash.ShockwaveFlash'.
>  May 25, 2013 10:34:19 AM com.gargoylesoftware.htmlunit.javascript.StrictErrorReporter runtimeError
>  SEVERE: runtimeError: message=[Automation server can't create object for 'ShockwaveFlash.ShockwaveFlash'.] sourceName=[http://www.google-analytics.com/ga.js] line=[25] lineSource=[null] lineOffset=[0]
>  May 25, 2013 10:34:20 AM com.gargoylesoftware.htmlunit.IncorrectnessListenerImpl notify
>  WARNING: Obsolete content type encountered: 'application/x-javascript'.
>  May 25, 2013 10:34:21 AM org.apache.http.client.protocol.ResponseProcessCookies processCookies
>  WARNING: Invalid cookie header: "Set-Cookie: azk-views=; Max-Age=31536000000; Path=/; Expires=Sun, 25 May 2014 17:34:42 GMT". Invalid max-age attribute: 31536000000
>  May 25, 2013 10:34:21 AM org.apache.http.client.protocol.ResponseProcessCookies processCookies
>  WARNING: Invalid cookie header: "Set-Cookie: azk-events=; Max-Age=2592000000; Path=/; Expires=Mon, 24 Jun 2013 17:34:42 GMT". Invalid max-age attribute: 2592000000
>  May 25, 2013 10:34:21 AM org.apache.http.client.protocol.ResponseProcessCookies processCookies
>  WARNING: Invalid cookie header: "Set-Cookie: azk-voting=; Max-Age=2592000000; Path=/; Expires=Mon, 24 Jun 2013 17:34:42 GMT". Invalid max-age attribute: 2592000000
>  May 25, 2013 10:34:21 AM com.gargoylesoftware.htmlunit.IncorrectnessListenerImpl notify
>  WARNING: Obsolete content type encountered: 'text/javascript'.
>  May 25, 2013 10:34:23 AM com.gargoylesoftware.htmlunit.javascript.background.JavaScriptJobManagerImpl runSingleJob
>  SEVERE: Job run failed with unexpected RuntimeException: Exception invoking setInnerHTML
> 
> 
>