Update failure :"Package system is broken" - by: Maxchess

Hi,
Just tried to update my Stellarmate on RPI 3 using the Software update button. after successfully checking for updates and giving me a list I get the following message when I try to start the update:

The Package System is broken, Check if you are using third party repositories, if so disable them......

I have run the updater before with no problems, also tried updating only PHD from the checklist.
don't really want to re-install as I will lose all my settings

Any ideas?
Max