I had the same issue on a fresh install of 16.04, after installing the brother drivers with their automatic script.
I ran an strace of simple-scan, as recommended by Kuwanger in the IRC, and found that simple-scan didn't have permission to access some cache files.
The problem was that simple-scan's cache files were owned by root, and not accessible by the user. The solution was to run
sudo chown -R <yourusername> ~/.cache/simple-scan
Of course, replace <yourusername> with the name of your user. I hope that helps!
I had the same issue on a fresh install of 16.04, after installing the brother drivers with their automatic script.
I ran an strace of simple-scan, as recommended by Kuwanger in the IRC, and found that simple-scan didn't have permission to access some cache files.
The problem was that simple-scan's cache files were owned by root, and not accessible by the user. The solution was to run
sudo chown -R <yourusername> ~/.cache/ simple- scan
Of course, replace <yourusername> with the name of your user. I hope that helps!