Symptom - after upgrade to Leap 15.6, Icons and links not showing on desktop.
What I found was that the “Extensions” software had not upgraded properly and was not functional.
After forcing an update on “Extensions”, the icons STILL didn’t show. Other related files were also set to “unconditional Update”.
I have “Main Menu” installed (which I use fairly often). I found that the usual “Extensions” in “Other” did not have the path to the program. Then while checking some other things, I found that I now had “Extensions” under “Accessories” but it wasn’t enabled. When I turned that on, I could then access the extensions I regularly use and turned them on. A minute or so later, and the Icons appeared.
My gut reaction was that “Extensions” was kept at 15.4 or not properly replaced upon the Upgrade.