I just installed AC27 with the update. The first project I opened up is an AC26 project and none of the custom Surfaces imported. How can I make this happen globally?
2.3 GHz 18-Core Intel Xeon W
Radeon Pro Vega 64 16 GB
128 GB 2666 MHz DDR4
Surfaces are attribute that are saved in the file, so all the surfaces you had in the 26 file should still be there when you open it in 27.
The textures used for the surfaces are saved in a library, so make sure you have the same libraries loaded if you used custom libraries.
If you just use the default libraries, you may need to load the migration libraries as well (although I doubt this affects surfaces).
Black and purple squares means the texture image is missing - the surfaces are there but the texture images used in those surfaces are not in a loaded library.
Check your Library Manger and in the warnings you will see all of the missing textures.
It may even show a missing library that you need to load.
As soon as you load the library with the texture files in it, it should all be good.
So after shutting everything down and just walking away... the next attempt to open AC27 with the same previous file, everything came in as it should have. Baffling to say the least, but at least baffling on the good side today.