XnView Software

OK - I think I have a solution - partial at least.
Went to Tools -> Preferences -> Database, Clicked Optimize, and ticked all of the options.
It now seems to be working, and has recovered all the settings I made last night.
problem in the database?

I have had this problem a number of times but have not been able to fully nail it down until now.
One persistent bug has been as follows:
Open one or more jpegs in separate tabs
While viewing the last one opened, close the tab
XnView crashes
All ratings and colour labels are lost for the current ...