So let's sum up: Williamson says that Labour have apologised too much for antisemitism, and - as far as I can see - still hasn't cancelled showing the Jackie Walker film in parliament. A film alleging Walker's treatment is a witch hunt.
As Winegums said, Jackie Walker has called for greater focus on other victims of the holocaust on holocaust memorial day. That in isolation is not necessarily unfair comment - holocaust memorial day (in the UK at least) is supposed to be in remembrance of all victims of all holocausts, not just the Jewish victims of the Nazis in WW2.
However, Jackie Walker has also said the Jews were financiers of the sugar and slave trade, and of course that she cannot find a definition of antisemitism she can work with. The former is simply antisemitism, be it from ignorance or malice - the effect is the same in attempting to label a whole people with a shameful act, wth the usual inference that Jews control all the money etc. The latter, in the context of everything else, seems to be a complaint that she cannot go as far as she would like to in her criticisms.
And Williamson has got off with an apology, it seems. One with many caveats undermining any actual element of apology. And Corbyn has previously defended him as well.
So if anyone wants to know why Labour have an antisemitism problem, here's one event that encapsulates the whole thing: someone who themselves has a history of at best what could be described as a lack of empathy and an antagonistic attitude getting a let off and not even a suspension by the party leader for (1) making awful statements and (2) exhibiting rank carelessness in booking an official function in parliament to show a film, itself claiming that the suspension of a high-ranking member of the body set up to specifically support the party leader was a stitch-up, despite what she said and the pattern of what she has said being a matter of record.
NONE of this is bad faith media. NONE of the events are in dispute. NONE of this is embellished, made up, extrapolated. Corbyn has failed to act, again. Williamson has been allowed to provoke, again. The signal has been sent down the ranks that you can be abusive and face no real consequences, again.
Once Williamson has had the whip removed, by Corbyn, and written an apology that's sorry for what he did not sorry for being caught, perhaps it will be possible to look at this topic again. Until such time, 'Labour has a problem with antisemitism' is fact, not opinion.