We have an enterprise app that heavily uses modal dialogs. This morning we were greeted with a flood of support requests that after a Windows update last night, dialogs no longer work.
We isolated the issue that window.dialogArguments on secondary window no longer works.
I have a test case below that you can verify, window.dialogArguments in test2.html shows 'undefined' on machines that have the KB3008923 update, but "[object Object]" when the update is uninstalled:
test0.html:
<!DOCTYPE html><html><body><button onclick="window.showModalDialog('test1.html',new Object());">clickme</button></body></html>test1.html:
<!DOCTYPE html><html><head><script>
alert(window.dialogArguments);</script></head><body><button onclick="window.showModalDialog('test2.html',new Object());">clickme</button></body></html>test2.html:
<!DOCTYPE html><html><head><script> alert(window.dialogArguments);</script></head><body></body></html>