Performed clean install v7.4.3 on Ubuntu 14.03 lts (LEMP stack) for testing and could not get Call reminder pop up to fire. I then upgraded my working in-production v7.3.1. on same server stack to v7.4.3. Now the working in-production version Call popup reminder no longer works.
During some troubleshooting I successfully sent email reminder to invitee which contained the traditional three selections Accept this call, Tentatively Accept this call, Decline this call as expected. When I select both pop up reminder and send email to invitees the result is two emails. One with the traditional three selections as expected and the second one reminding me of the call.
It seems that a second unexpected email reminding me to call is being sent instead of firing the popup.
Please Help
LJC