UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Steps to reproduce the problem:
Intermittent crash but numerous times a day for many of our users using chrome

What is the expected behavior?
No crashing

What went wrong?
A radwindow closes, the tab refreshes and returns a "Page cannot be displayed" message.  Numerous users all using chrome.  This did not happen before release 66.  All dump files return the message of "The thread tried to read orr write to a virtual address for which it does not have the appropriate access".  Debugging the dmp files shows "ownerLayoutObject was nullptr".  These are all at line 1314 of CompositedLayerMapping.cpp file at     graphics_layer_parent_location =
        -FlooredIntPoint(FrameOwnerContentsLocation());

Crashed report ID: 

How much crashed? Just one tab

Is it a problem with a plugin? N/A 

Did this work before? Yes Chrome 65

Chrome version: 66.0.3359.139  Channel: stable
OS Version: 10.0
Flash Version:
 

Deleted: 9e5ccc1c-3a18-459f-af9f-fcf5cdf80693.dmp 754 KB

9e5ccc1c-3a18-459f-af9f-fcf5cdf80693.dmp 754 KB Download