in server/src/jetbrains/buildServer/serverSide/priority/PriorityClassImpl.java [157:164]
public static void checkNameIsCorrect(@NotNull String name) {
if (name.trim().length() == 0) {
throw new InvalidPriorityClassNameException("The name must be specified");
}
if (name.trim().length() > 255) {
throw new InvalidPriorityClassNameException("The name is too long");
}
}