Install GladeVCP on Raspberry Pi 4

If you have any suggestions that I could try in order to get this solved I would of course be very happy to hear them.

The name of your GtkWindow is "window", right? It has to be "window1". Documented here: www.linuxcnc.org/docs/2.9/html/gui/glade...a_new_user_interface

Thank you for your quick help!
Although I read the documentation while I was installing it, I did not understand that part as I couldn't find anything in Glade that mentions "window1". But as the documentation describes that this is the default anyway I thought it would not cause any issue.
However, if I would need to change "window" to "window1" as you mentioned it would be of importance of course.

I searched for it again but I have not been able to find anything that mentions either "window" or "window1". (I only see it in the documentation screenshots, but Glade looks very differently on my device.)
Do you perhaps refer to the "Widget name" field in the "Common" tab? Or perhaps does it refer to the "ID" field in the "General" tab?
Both fields are empty by default, but if I enter "window1" the error still persists.

It should be the id in the General tab:

By default the "ID" field in the "General" tab was empty, but after I entered the text "window1" in this field the error stays the same unfortunately.

 

By default the "ID" field in the "General" tab was empty,

Seems that the behavior in the "new" glade versions has changed. I will add that to the documentation.

but after I entered the text "window1" in this field the error stays the same unfortunately.

You have to name the GtkWindow "window1" not your HAL_LED. Pay attention what you have selected in the left panel:

 

Hi HansU,
I am sorry for my late reply (I didn't have a lot of time unfortunately lately to play around with my RPi) but I tried this and it did indeed solve my issue. I am now able to build a nice and functioning GUI, something I was looking forward to for a long time.
Thank you!