To solve the problem which sometimes occurs in chromium showing, when you start it, a popup "Your profile could not be opened correctly" in Ubuntu.
open a terminal and execute the following command:
mv ~/.config/chromium/Default ~/.config/chromium/Backup
Then start chromium, all will be ok, close it and in a terminal execute the following two lines:
rm -rf ~/.config/chromium/Default
cp -R ~/.config/chromium/Backup ~/.config/chromium/Default
Now open your browser and the issue is fixed!