You have to make sure that the *.so file is discoverable. First, check that in the folder ~/projects/Urho3D-1.5/build/lib you have:
valera@valera-HP-ENVY-17-Notebook-PC:~/projects/Urho3D-1.5/build/lib$ ls -a -h -l
total 22M
drwxrwxr-x 2 valera valera 24 Jan 21 09:15 .
drwxrwxr-x 8 valera valera 4.0K Jan 21 09:11 ..
lrwxrwxrwx 1 valera valera 14 Jan 21 09:15 libUrho3D.so -> libUrho3D.so.0
lrwxrwxrwx 1 valera valera 20 Jan 21 09:15 libUrho3D.so.0 -> libUrho3D.so.0.0.171
-rwxrwxr-x 1 valera valera 22M Jan 21 09:15 libUrho3D.so.0.0.171
Then create the file /etc/ld.so.conf.d/urho3d.conf, and add the following line to it:
Then run the command:
Of course, modify the paths according to your setup.
PS: In the video I also do these steps. Maybe you didn’t notice them?