Darktable will no longer start from GNOME icon [Solved]

Software darktable
1

Fine until this morning. But today, darktable is not starting if I press the GNOME desktop icon for it.

This contains:

Exec=/opt/darktable/bin/darktable %U
TryExec=/opt/darktable/bin/darktable

If I type

/opt/darktable/bin/darktable

from the command line, it works fine.

If I type

/opt/darktable/bin/darktable %U

from the command-line, I get:

(darktable:64358): dbind-WARNING **: 15:18:09.822: Couldn’t connect to accessibility bus: Failed to connect to socket /root/.cache/at-spi/bus_1: Permission denied
path lookup ‘/home/colinadams/%U’ fails with: ‘No such file or directory’

2

and now, after adding:

export NO_AT_BRIDGE=1

to my .bash_profile, to turn off the dbind-WARNING (and logging out and in again), it’s working, but the icon has reverted to the default. I feel like I am chasing my tail with this gnome icon business.

3

but the latter was easily solved