Warning: simplexml_load_string() in Magento

This error comes when there is any unwanted white space in any file or in the URL path.

To fix this error you need to connect to the database and open table core_config_data.

find web/unsecure/base_url and web/secure/base_url URL in this table.

check domain URL contains white space or not if yes then remove and save it.

now clear cache from var folder and run URL.