Productions that want the play to have a real happy ending try hard to make Bertram come across as a likable but callow youth who needs to learn some valuable lessons in life rather than a shallow Jerkass who clearly isn't good enough for Helena, usually by casting a really, really handsome and charismatic actor in his role, and playing up Parolles as a bad influence. It doesn't always work.
Since Helena's determined affection for a total loser with no redeeming qualities who hates her guts is so inexplicable, there's also some debate on whether to portray her as the nice, sensible if lovestruck girl she mostly seems to be, or as some kind of slightly unhinged Love Freak or Yandere. Thinking about it, Helena's fixation on him may have some psychologicalreasons. Other productions instead settle on making her a Love Martyr who's entirely conscious of Bertram's horrible behavior, but also self-aware enough to know that she'll never love anyone else as much as him; as such, her attempts to win him over are also attempts to correct his flaws and help him mature.
Bertram's seemingly Irrational Hatred for Helena may be resentment for being arbitrarily banned from his ambitions in order to get married instead, since in the beginning of the play he was just politely ignoring her. Even then, taking a dislike in her wouldn't have been completelybaseless.
Esoteric Happy Ending: The play seems to be a comedy, so some commentators have argued that the finale — where the lovely, sweet and clever Helena has succeeded in marrying Bertram, an utter tool who hated her guts for most of the play — must have been intended to be seen as happy. Somehow.
Lampshaded, in some productions, by the way one of the King's final lines is delivered:
King:(uncertainly) All yet seems well...
Values Dissonance: Helena and Diana make and carry out a plan for Helena to sneak into Bertram's bed in place of Diana in order to fulfill the conditions of his challenge to her. When Bertram learns of it, he is... impressed by her cunning and falls in love with her. This can be more than a bit shocking to modern audiences, given that this sort of deception is now considered a form of rape.
Values Resonance: Though Helena's Bed Trick described above is uncomfortable to contemporary audiences, she's also a proactive heroine who, unlike characters like Portia and Rosalind, doesn't disguise herself as a man to take a lead role in the story. Helena is also a skilled doctor and chemist, given that she uses a Healing Herb to cure the King's illness, which has stumped the best medical minds in the realm—this was at a time when the very idea of a woman practicing medicine was an impossibility. And, while she can be portrayed as being unhealthily fixated on Bertram, all the other characters acknowledge that his treatment of her is utterly awful.
