Hi,
I'm trying to use Google Calendar so I can set alarms on Kalarm on a remote computer running Ubuntu 14.04. I have various problems:

After adding Google calendar to the Active Alarms list, Kalarm sometimes crashes.
I cannot seem to find anywhere to set my Google Calendar as the "default" calendar either before or after removing the pre-supplied "Active Alarms" calendar.
Possibly as a related issue, I cannot save any new alarms, getting the message "You must select a calendar to save the alarm in" upon clicking "OK".

If there is some other way of remotely setting alarms on Kalarm I would be glad to use them: I'm not bothered about using Google calendar.
I have tried using Korganizer to merge with the Google Calendar and then to add the local Korganizer .ics file to create a new alarm calendar, but I still get the "You must select a calendar to save the alarm in" message.

Thanks in advance for any advice.

There is currently no facility in KAlarm to use Google calendar. It is on the list of features to implement, but there is not likely to be time to do this in the near future.

Although KAlarm can read KOrganizer calendars, it cannot write to them. This is because KAlarm has various additional alarm features and therefore needs to store extra custom data in its calendars, and only writes to its own calendars.

If you want to use a Google calendar, you should merge it using KOrganizer (as you have already done), and then use KAlarm's import function (menu File -> Import Alarms) to merge it into KAlarm's calendar. Note that only events with alarms will appear in KAlarm's calendar - if events don't have alarms, you will need to either set reminders for them in KOrganizer before importing into KAlarm, or create them afresh in KAlarm.

After the import, you should check each imported alarm to ensure that its trigger time and other details are correct.