I have created various events with reminders, the red bell icon is portrayed in the event slot, but not reminder window or notification is ever shown before the event. I experimented with different types of reminders: dialogue window, e-mail notification, etc, but nothing happens.

Note: I have version 4.13.3 installed, which is not in the list.

Reproducible: Always

Steps to Reproduce:
1. Double click on the calendar to create a new event (say half an hour from now).
2. In the Reminder tab click the "Add" button and then "Ok".
3. Wait until the even starting time.

Actual Results:  
No dialogue window was ever shown. No reminder e-mail was sent.

Expected Results:  
Some sort of dialogue window pop-ing up or a reminder in the Dash. An e-mail reminder.

This issue was discussed in the users maillist:
https://marc.info/?l=kdepim-users&m=145867021502527&w=2