Answer
This is caused by enablement of Chrome’s “block third party cookies” setting. To fix this error without disabling that feature, add an “allow” exception for the plugin.
Step 1: Get the ID of your Threat Response plugin.
1.1 Right click the plugin button and in the resulting drop down select Manage Extensions
1.2 The resulting page will have a URL like chrome://extensions/?id=ID_STRING
1.3 Copy that ID_STRING into your clipboard
Step 2: Create the allow rule
2.1 Go to Chrome’s cookie management page in settings (chrome://settings/content/cookies)
2.2 In the allow section, click “add”
2.3 In the Site field, enter chrome-extension://ID_STRING/ replacing the ID_STRING with the string from step 1.3
Step 3: Verify
3.1 The Allow section of the cookie settings page should now have an entry for Cisco Threat Response Casebook.
