If you respond to a meeting invitation from Outlook (using the Yes/Maybe/No links as instructed), you may receive an XML error. You can prevent this error by changing a setting in Internet Explorer. Follow the steps below.
Open Internet Explorer.
Go to the Tools menu, then click Internet Options.
Click the Security tab, then click Local Intranet.
Click the Custom level... button.
In the list of Settings, scroll down to the Miscellaneous section. Then change the Access data sources across domains setting to Enable.