The error messages in Dolphin (I will add a screenshot) are very confusing to me, because they contain two icons with an X in them. One like this [x] and one like that (x). So they appear pretty similar, but only one of them is click able and actually closes the error message. Somehow the reflex often drives me to the wrong icon, even though I should just know that it does nothing. I assume that I am not the only one who makes this mistake. So I would like to suggest to chance the [x] icon into another one. May be the blue (!) exclamation-mark icon which shortly shown when a new usb-stick is plugged in (in plasma desktop) could make the difference clearer. An exclamation mark normally means attention which is what the user should have when the error appears. Appart from that the error message in the screenshot (indicating that Nepomuk is not running) may be should also offer to start it.
Created attachment 80801 [details]
Thanks for the report. Already fixed in kdelibs 4.11.
*** This bug has been marked as a duplicate of bug 304775 ***