I am having this problem on Ubuntu 18.04 -- I manage a batch of desktop machines with some convience desktop launchers, which gnome3 insists are "untrusted". With some general websearching reveals that this is a *GNome3* so-called "security" issue (https://gitlab.gnome.org/GNOME/nautilus/commit/1630f5348). I found a thread on the CentOS Forums (I don't have an account there), where another sysadmin is strugling with this issue:
https://www.centos.org/forums/viewtopic.php?f=47&t=65864&start=10
If anyone has come up with a script that can be dropped into ~/.config/autostart/ to "fix" this "feature" of gnome3 I would be interested in it.