I have a BO with plaintext choicelist with two values: Yes and No.
I've added a locale and translated every "Yes" and "No" value to "Ja" and "Nee"
When saving the BO in runtime, the system says:
"Acceptable values for attribute are: Yes, No" (I even translated this message, but no solution)
I've seen other (old) issues about this problem, but it should be fixed a long time ago.