Error Troubleshooting

XMLHttpRequest cannot load XXX

Symptom

You get the error

XMLHttpRequest cannot load xxxxx. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://xxxxxxx' is therefore not allowed access.

Cause

You are uploading or downloading to/from a web server which is in a different domain than your current website and that web server doesn’t allow accessing from a different domain.

Solution

Try uploading to the same domain or update the server side configuration to allow cross domain requests. If you are using IIS, you can refer to the following configuration.

<system.webServer>
    <httpProtocol>
            <customHeaders>
            <add name="Access-Control-Allow-Origin" value="*" />
            <add name="Access-Control-Allow-Methods" value="OPTIONS, POST, GET, PUT" />
            <add name="Access-Control-Allow-Headers" value="x-requested-with" />
            <add name="Access-Control-Allow-Credentials" value="true" />
        </customHeaders>
    </httpProtocol>
</system.webServer>

Note

After updating the server configuration file, you’ll need to restart the server (i.e. IIS).

If you are downloading a file, you might need to clear the browser cache because a cached file will not be requested again from the server, thus still no ‘Access-Control-Allow-Origin’ header will be presented.

If you are using Windows Authentication, you may need to change the default setting of withCredentials in the dynamsoft.webtwain.initiate.js file. To do that, open the JS file, find withCredentials:false and change it to withCredentials:true .