Hello again.
I installed the New Lifestyle quickstart file and have been happily using it.

I did make an oops and overwrote the New Lifestyle - Sub Page style with one of my own, instead of making a copy. Since I want to continue to see all of the demo content, I recreated it with the name New Lifestyle - Sub Page. I can now happily open the demo content pages.

I say all of this only as background - in case there is some bearing on my present problem:
When I am in Template Manager and I go to Templates and open New Lifestyle Details and Files, I see the error in the attached image. Any ideas?

Thanks.
Pat

Can you try re-installing the template (you don't need to delete anything)

Cheers
Paul

How does one do that, and does it affect any work done up until now?

With T3 templates just install the blank template download from the Joomla Bamboo template page

It shouldn't affect anything but its always a good idea to have a back up in place

Cheers
Paul