Error: Error: Unable to initialize GTK+, is DISPLAY set properly? On Debian v.10

[pschait]

Hi.
I've downloaded and run without problem the Linux v.10.3.
Since I'm happy I donate for the Donation Version. I received a link and downloaded the FreeFileSync_11.3_[Donation_Edition]_Linux.zip version.

I'm trying to use the donation version but I get following error:
Error: Unable to initialize GTK+, is DISPLAY set properly?

What I'm missing here?
Could the donation version require any specifc Linux Debian 10 environment?
What should I do to use the donation version?

At the moment I'm using the free one which works in the same environment.... (Debian 10).

[pschait]

Maybe because the "linux donation version" does not have any key in his folder (FreeFileSync_11.3_[Donation_Edition]_Setup.key).
The other MacOS, Win, and Portable have each one key.

I wait for a confirmation and a solution?

[Plerry]

See the (2nd) reply to this post

[pschait]

Thank you Mr. Plerry.

I need to correct my first post.

I've downloaded and run the Linux v.11.3 without problem (errounesly I wrote v.10.3).
Then I received the Donation Edition v.11.3 which doesnt't work

The only difference is the key?

Free 11.3 works perfectly on Linux.
Donation 11.3 dont.

Any hint?
Btw: the Plerry above suggestion does't help. :-(

[bgstack15]

The error message states that the DISPLAY value is not giving GTK enough information about the display. Basically, it doesn't know what graphical display to use. This is a really unusual error to get if you are running the program by selecting the binary itself from a graphical file manager.

Debian 10-- is that using Xfce by default? I'm not sure that Debian has a default desktop environment. That isn't too relevant, but it just might matter.

Anyways, if you are running the FreeFileSync binary from the command line, you want to make sure that you set the environment variable DISPLAY to a useful value. Your login session on the main screen of the computer is probably going to be DISPLAY=:0
So, you would run:

DISPLAY=:0 /path/to/FreeFileSync_x86_64


And replace the path of course. It would be acceptable to run this from the current directory with the FreeFileSync binary:

DISPLAY=:0 ./FreeFileSync_x86_64


If you are running this in VNC or some other remote connection tool, those generally start with DISPLAY=:10 and sometimes they have an extra decimal and zero, so DISPLAY=:10.0. I cannot remember why.
If for some reason you are not using DISPLAY=:0 or :1 then we could investigate discovering what the DISPLAY value is but I won't drown you in those crazy commands just yet.

[pschait]

Thank you.
I'm logging in the system with the Ubuntu GUI Gnome. I then open a terminal as sudo.
The DISPLAY env is =:0
I run FFS from the CMD.
I get now the error "protocol error".
After googling a bit. I've found that instead as logging in the system with the GUI Gnome, I need to login as Xorg on Gnome.
Logged in as Xorg on Gnome and now FFS opens as expected !