Moonfruit suggest it might be a rendering problem and have suggested I uninstall Flash Player and reinstall it.
This problem has only occurred in the past two weeks. I've made no changes to my computer setup.
I'm using an iMac 2.7 GHz Intel Core i5.
Google Chrome is my default browser (which I'm told has Flash Player built in).
I use Adobe Cloud, and in my Flash folder there are:
two Flash Player apps which appear to be identical (same date, same version)
Four Flash Player folders
3 x Flash Player Debugger (all the same date, two times at 18.55, the other timed at 19:00. Two are version 11.2.202.228; the other is v11.1.102.55
6xFlash Player.plugin of varying versions and dates (and in different folders)
I'm not good at this stuff and very confused. If I uninstall, will I do damage to anything else?