Error on 'Save as database'

[timothy]

Hi
KMyMoney Version 4.8.1-ebeeced071
Using KDE Development Platform 4.14.2
Running on LMDE 2 O/S

I get the following error during 'Save to database'
--------------------------------
Sorry-KMyMoney
Cannot save to current database: Error in function void
MyMoneyStorageSql::writeSchedule(const MyMoneySchedule&, QSqlQuery&,
bool) : writing Schedules
Driver = QSQLITE, Host = localhost, User = timothy, Database
= /home/timothy/data/sqlite/test.db
Driver Error: 
Database Error No -1: 
Text:  
Error type 0
Executed: INSERT INTO kmmSchedules (id, name, type, typeString,
occurence, occurenceMultiplier, occurenceString, paymentType,
paymentTypeString, startDate, endDate, fixed, lastDayInMonth, autoEnter,
lastPayment, nextPaymentDue, weekendOption, weekendOptionString) VALUES
(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);
Query error No 19: NOT NULL constraint failed: kmmSchedules.startDate
Unable to fetch row
Error type 1
-------------------------------------

My data is consistent.
The database file is created by KMM and tables, views etc are also
created with the appropriate column headings, but no values/data are
inserted.
I tried creating the db file separately, but got the same error.

I tried on Linux Mint 19 with Kmymoney 5 with the same kmm file and got
the same error with the same db configuration.

Is there something wrong with my .kmy file? How does the database handle
the numerator/denominator format of some kmm values? Am I doing or not
doing something to cause the error?

Any help please.

Regards
Timothy