I've setup a Siemens MC35 gsm modem pointing to /dev/ttyS0 which works fine with minicom.
Next step was setting up those parameters in zabbix, and adding a media SMS to a user.

[IMG]https://i.imgur.com/XhZKVJ6.png[/IMG]

However when an alert is sent I'm getting an error message in the action log:

no media defined for user "Zabbix Administrator"

When I add an Email alert this works fine.
I also tried to add SMS to another user, but I'm getting the same message there. Also tried to remove media type and readding it didn't help.
Further I also added the "zabbix" user to the "dialout" group.

Any suggestions? Is this a bug? I'm using zabbix v3.2.4