Bug: Does not recognise "execute on"

[KotiasFeet]

Can not write "execute on" commands. None of the existing "on" commands are getting recognised.

execute on attacker run say hello
execute on controller run say hello
execute on leasher run say hello
execute on origin run say hello
execute on owner run say hello
execute on vehicle run say hello
execute on target run say hello

[Nico314159]

What is your pack_format in the pack.mcmeta file?