This is a simple permissions problem and deselecting it for backup as indicated in this answer will certainly work. Another method would be to insure that the ownership and permissions match everything else in your home directory. For example:
drwx------ 2 me me 4.0K Mar 21 15:18 dconf where me is your user name.
If that directory (~/.cache/dconf) is owned by another user you can use the chown command to set it back to your user as is typical. You could simply use the command sudo chown $USER:$USER .cache/dconf as the $USER environment variable should contain your user name. You can test that it's set properly with the command echo $USER which should return your user name.
Further if the permissions don't match, those can be set back using the chmod command In order to backup a directory, both the read and execute permissions are required. (You need execute permission to traverse a directory.) To set the permissions simply use the command chmod +rwx ~/.cache/dconf to insure that the read write and execute bits are set for the directory in question.
Note ~ is the same as your home directory and expands to /home/jackie/ in your case. You can confirm this as well using the command echo ~
Note: Backing up your home directory will not backup "all the applications and settings" Many applications/programs are launched from locations that are not in your home directory. You can find out easily by using the command which for example the command which rsync will report the rsync lives in the /usr/bin directory (along with many others). and which zcat will report that zcat lives in the /bin directory with a few good friends. Since I'm personally not too concerned about how much storage I use for backing up and like ease of restoration this is my favorite backup method.