Large policies can fail to load

When selecting a policy from Insights->Manage Policies, some larger policies can fail to load.

Problem

When selecting a policy from Insights->Manage Policies, the policy will not load and displays the following error:
An error occurred while fetching data from the server. Please make sure you have an active internet connection. More...

Resolution

You may sometimes hit this issue if you open a policy which has a large number of event group instances.

Draft comment: LOUISERoberts
#1434