Hi.
This is something I do when all my permissions are greyed out in KDE.
A) Open Dolphin
file manager.
B) Right click on the ~/.firefox
folder.
C) Choose Properties
.
D) Go to the Permissions
tab.
E) Click Advanced Permissions
.
F) Make sure that all Special ticks (UID, GID, Sticky)
are unticked.
G) Click Ok
.
H) Are Your permissions still not available? They should be now.
I) Set them up
a) Owner: Can view and modify content
b) Group: Forbidden
c) Others: Forbidden.
J) Mark the box "Only owner can rename and delete folder content"
..
K) Make sure that Your login
. is present in Owner and Group dropdown menu.
L) Mark the box "Apply changes to all subfolders and their content"
.
M) Click OK
.
This should finish with no errors.
You should be good to go.
Andy