Here is a quick tip. The fastest way to resolve Dolphin crashes in KDE4 is to do a clean re-install of the Dolphin package from your package manager. Unfortunately, this doesn't always work, as even after reinstalling or upgrading the Dolphin package, the error remains unresolved.The reason is that the configuration files are not cleared when you re-install, so we need to remove them manually.
This is what you need to do.
1.Remove/Uninstall Dolphin from your package manager.
2.Locate all the Dolphin configuration files on your system, and rename or delete them.
3.Now install the Dolphin package again.
4.Restart your machine (this one is optional but recommended)
Great, Dolphin is back.
Now, if you still can't fix it, then let's see what alternatives we have..
I personally use this really great KDE file manager called Krusader
Do drop me a note, if you have any other recommendations for other alternative file managers.