I was trying to do a search using Dolphin file manager and, when I start typing the file name in the search box, I get the message "Invalid protocol" after the first 4 characters and I cannot do the search. I want to do the search on my hard drive. What does the message mean? I have a screen shot of the error but I can't figure out how to post it here.
Possibly you have uninstalled konqueror and its libraries, try installing kfind package from the terminal (Konsole):