Using Dolphin 16.04.3 (and earlier), previewing .mp3 files that have a % sign in the file name prevents from playing its preview. This may occur for other media files but only mp3 were tested. How to duplicate: Find an .mp3 file, for example: "02 - Mia.mp3" and then highlight it in Dolphin. In the right Information pane, click the circular play button. The mp3 should play just fine. Now rename the file to "02 - Mia 10%.mp3" (note the % symbol). Re-highlight the file and move over to the Information pane at the right of Dolphin. Click the circular play button. Nothing happens, no audio playback.
I cannot reproduce, works fine here even with a % symbol in the filename. What's your phonon backend?
Hello Elvis. I have the same Phonon GStreamer 4.8.2
Anyway Dolphin just uses the widget provided by phonon. Moving to phonon component.
I can confirm that this happens for me too with Frameworks 5.28.0, Qt 5.6.1, Plasma 5.8.5 and GStreamer 4.8.2 all under Kubuntu 16.10.
Tested and can confirm this is now fixed in KDE neon latest packages.