2017-12-09 jj5 – TODO: document this on my blog…
On Debian GNU/Linux 9.1 (stretch) when I try to open an *.desktop (application/x-desktop) link in a browser I get:
A folder named ~/.cache/kioexec/krun/13821_0/ already exists.
A folder named kioexec krun already exists
turned up diddly squat.
I solved the issue (for me) by changing:
System Settings -> Personalization -> Applications -> Default Application s-> Web Browser
Open http and https URLs in an application based on the contents of the URL
Open http and https URLs in the following browser: firefox