Validation messages are wrong: parameters are not substitued, some '

{0}' are displayed instead.

if the message template contains '''{0}

''' (3x apostrophes), the final message will look like ... '

{0}'... , even if the arg was "foo"
on the other hand, if the message template only contains ''{0}

'' (2x apostrophes) with arg "foo", the final message will look like ... 'foo' ...