I updated all my CC apps last night, and this morning moved Actions and Scripts from the 2015.5 folder, I also moved Brushes from 2015 [all the 2017 folders had gone, but 2015.5, 2015 and 2014 folders remained)] Administrator rights were required ... which I thought a bit odd.
I loaded a set of actions [BTW, when is Adobe going to allow multiple Actions to be loaded in one go?], modified an Action, and tried to save the set. Windows denied access, reporting the file was locked. Sure enough, the file permissions were insufficient (no Modify or Write access). I fixed this, and tried again. Same result. Then I checked the folder rights [I know I should have done this at the start]. Same again, insufficient access.
The same applied to all folders under Programs/Adobe/Photoshop 2018/Presets/.
I amended all folder rights, and saving is now OK.
Anyone else experienced this? It has not happened previously,; for example the recent 2017 update did not exhibit this behaviour.