There's a default value already in SOGoDefaults.plist:

https://github.com/inverse-inc/sogo/blob/maint/SoObjects/SOGo/SOGoDefaults.plist#L72

Sorry, but "NONE" is not a valid setting for SOGoCalendarDefaultReminder according to the "SOGo Installation Guide" page 37.

So this doesn't work.
See also
http://www.mail-archive.com/users%40sogo.nu/msg17362.html

I can't reproduce the problem. SOGoCalendarDefaultReminder is not defined in my configuration nor set in my user defaults and I don't have any error.

I updated another server (CentOS 5) to 2.2.0 yesterday.
I didn't set SOGoCalendarDefaultReminder in /etc/sogo/sogo.conf.
Strangely the error didn't happen for me too.
Perhaps this is OS dependant?

See also
http://www.mail-archive.com/users%40sogo.nu/msg17383.html

Anyway. If "NONE" is a valid value for SOGoCalendarDefaultReminder, then the "SOGo Installation Guide" page 37 should say so.
And it should mention that it is the default.

What is the platform on which you have the exception? Do you use packages?

I had it with a nightly build on CentOS 5.
Sorry don't remember which one.

Afterwards I always set SOGoCalendarDefaultReminder, so I didn't get it later.
But other people seem to hav it as per the mailinglist.

Fixed.

See https://github.com/inverse-inc/sogo/commit/0c99323db3e5404301c249512b736d426bd41d09