This usually indicates a crash inside the browser engine. In order to resolve this issue, we must identify the root of the crash and resolve the crash.
If you have a way to reproduce this issue, please try to isolate the problem into a test project and send the test project to us. See here for more details:https://www.essentialobjects.com/forum/test_project.aspx
To reproduce the issue is the most reliable way to resolve the issue since not only it helps us to identify the issue quickly, but also provides a way to verify the fix.
If it is not possible to reproduce the issue, please try to capture crash log:https://www.essentialobjects.com/doc/common/crash_report
Once we receive the crash log, we will look into it and see what we can find.