Dolphin, the new KDE file manager (entirely replaced Konqueror, which now serves as a web browser only) still has some teething problems. The main problem I was facing was, whenever I closed Dolphin I got this annoying error message:

After some googleing, I’ve eventually found the solution to my Dolphin problem

sudo chown -R theresa:theresa /home/theresa/.kde (replace theresa with your username)

That did it for me, next time I opened Dolphin, I had no such error message again. God Bless!