In version 8.5 RU4 when using Chrome (supported starting with RU4), when creating an Emergency Policy Update on a Managed Software Delivery policy, after clicking OK on the initial pop-up, we see an error thrown when using Chrome. The Emergency Update Policy does run successfully as seen in the logs. No errors are seen in the logs.

When using Internet Explorer, it pops a new tab with the Emergency Policy Update Status Summary report as expected.
Steps to reproduce:
Using Chrome, navigate to Manage > Policies > Software > Managed Software Delivery.
Right click any Managed Software Delivery policy and select Emergency Policy Update
Click OK on the pop-up to get the error message.
In Internet Explorer, the error does not occur.