libre Office Base 5.1.6 creashes when I run reports

I have a database of financial transactions which has been in use for 3 years. I run annual end of year reports for taxation. Last year the reports rean. This year they fail. Base crashes when I open a predefined report which ran last year or when I try to create a new report. All other functions appear to work normally. The version information i have is:
Version: 5.1.6.2
Build ID: 1:5.1.6~rc2-0ubuntu1~xenial3
CPU Threads: 2; OS Version: Linux 4.4; UI Render: default;
Locale: en-AU (en_AU.UTF-8); Calc: group
It was build using the software in the Ubuntu Repository for 16.04