My ficus tree got sunburned while we were away, and the weather changed drastically here in Scotland to hot, sunny and dry.
The ficus is kept in our conservatory where it has thrived, but this summer we are having an exceptionally warm and dry summer. Suddenly after being away for a week we came back to find the leaves had all turned dry, brittle and bleached. Can this tree be saved? What do I do?
Water is life for a plant, so if it went dry while you were away that could be the primary reason for decline. I suspect more than one week of drought stress.
Sunburn is unlikely unless you moved it from inside a covered conservatory into the sunlight at the same time as it experienced water deficit.
Put the saucer back under the pot and give it a good soaking. Wait and see if it puts out new leaves from the stems and re-foliates.
By the way, from the photo I see girdling (circling) roots at the base. These can constrict and cut off uptake of water and nutrients. This could be part of the problem.