New widgets in old Glade files
Problem: disabled widgets in older Glade files
It may occur that certain widgets in Glade are greyed out after opened in Glade.
A hint is hown in tooltips like
The cause for this behaviour is the Gtk+ version given at the beginning of the file:
<?xml version="1.0" encoding="UTF-8"?> <!-- Generated with glade 3.20.1 --> <interface> <requires lib="gtk+" version="3.0"/> ...
This line will not be altered even if the file is saved by a more recent Glade version. So you just manually replace "3.0" by a current version ("3.20" at present).