For switching level 2 to 3 i used the same code for level 1 to 2 and it doesn't work The link to my project: https://scratch.mit.edu/projects/224757725/

Don't leave forever loops running after they've done their job. The keytouchedlevel1 script in Crown is still running its forever loop when you touch the Castle in level 2 so will again broadcast Level1Complete. That may not be the only thing happening but gives you the idea - either scripts handle multiple levels or they need to be stopped when they're complete. Deal with those issue and see if that fixes the problem.

change all your

when I receive [ v]
forever
if <touching [ v] ?> then
broadcast [ v]
end
end

to

when I receive [ v]
wait until <touching [ v] ?>
broadcast [ v]

so they stop after being used.