<p>This error just started popping up all over our site.</p>

<p><strong><em>Permission denied to call method to Location.toString</em></strong></p>

<p>I'm seeing google posts that suggest that this is related to flash and our crossdomain.xml.  What caused this to occur and how do you fix?</p>

Are you using javascript to communicate between frames/iframes which point to different domains? This is not permitted by the JS "same origin/domain" security policy. Ie, if you have
```
```
<iframe name="foo" src="foo.com/script.js">
<iframe name="bar" src="bar.com/script.js">
```
```
And the script on bar.com tries to access
```
window["foo"].Location.toString
```
, you will get this (or similar) exceptions. Please also note that the same origin policy can also kick in if you have content from different subdomains.
Here
you can find a short and to the point explanation of it with examples.