This used to work in previous versions of krusader and still works in the current version of the dolphin file manager - some sort of regression in krusader or kiomtpslave?
I can confirm this with version 2.4.0~beta3-2 under Debian. The "Open with File Manager" action from Device Notifier leads to a KIOExcec error giving "/devicename" as output. Dolphin however works.
Doesn't work for me too. Please fix.
*** This bug has been confirmed by popular vote. ***
The device detection in the Media button (CTRL+M) has never changed in the last 10 years. That detection is made through Solid framework; all devices that could be mounted are shown; I'll further investigate on it, as this involves solid, kio, and/or udev (or an equivalent). Actual Dolphin is "affected" too, but I shouldn't call this behaviour a "bug".
Thanks to Alexander Bikadorov work, mtp is available. https://quickgit.kde.org/?p=krusader.git&a=commit&h=b7ab125d78837cdc236424f6af17b86f24cd80ac This affects future Krusader (Plasma) only, the KDE4 version (2.4.0) won't be updated. Until the release, you can have a preview on the git version.