timers for switch in raspberry pi

[Dick60]

I am complete a newbi and read about Domoticz. Installed it on my Pi3 without any problems. I use an USB serial mySensor GW. I created a switch (relay) and it is visible in the Domoticz Devices list. Add it as a switch and can turn it on and of using the icon on the switch block. Now I try to add a timer, I can prepare the settings and if I push the ADD button it will not appear in the list of timers. It looks like the Add button does not react. I also installed Windows Domoticz and than I am able to use the add butten and the entry appears in the list.
Any ideas?

[Dick60]

I am a shame. The problem was that I tried to set the timers using Internet Explorer and that does not work. Using Chrome it worked fine. Sorry for this unnecessarry question.