writing or lack there of

Question: Can I get away with posting a fic with a placeholder in it? It has been five months since I've been able to write a single word on The Polyhex Candidate and I so hate to leave the thing hanging and unfinished as it is. Thing is, every time I go to work on it, the bunnies run away. I think that the issue is with my characterization of Ultra Magnus. I have one more scene involving him and I really NEED to have it in the story to move the plot forward but every time I try he comes across as totally out of character and indecisive/weak.

*sigh* So I need to write something. I need to get over this block ...