| layout | default-layout |
|---|---|
| noTitleIndex | true |
| needAutoGenerateSidebar | true |
| title | XMLHttpRequest cannot load XXX |
| keywords | Dynamic Web TWAIN, Error Troubleshooting, XMLHttpRequest |
| breadcrumbText | XMLHttpRequest cannot load XXX |
| description | XMLHttpRequest cannot load XXX |
| date | 2021-12-03 23:26:46 +0000 |
| last_modified | 2026-01-23 06:35:12 -0800 |
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.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.
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 need to send cookies/credentials (e.g., Windows Authentication), enable credentials via code:
DWTObject.HTTPRequestswithCredentials = true; // adds withCredentials:true on upload requests