I am running current with Plasma 5.
After the current update this morning, the desktop shortcuts no longer work. I can start them through the start button, so everything is working.

I tried to delete them, but it is as if I had a blank desktop. The desktop files are present, and I even tried deleting the one for Thunderbird and recreating it, but nothing changed on the screen. The Thunderbird icon is still present, but does not respond. After deleting the desktop file, the icon did not disappear.

Not sure what to try next. I think I will see if there is a way to nuke the whole screen and start over.

I updated current in vbox and this behavior did not happen. Vbox is simply a clean system with only Plasma 5 added.

The upper right desktop icon (cashew) is working. I'll figure it out eventually.....

All-righty, then....

Rebooted and all is well. I have no flippin' clue. Same procedure followed as for all upgrades - especially when a kernel is involved. So I didn't figure it out.