This appears to be a hotfix for an issue with running some homebrews. Translating the changelog from French to English, it says that this fixes an annoying bug: "...that prevented the launch of an entire category whose homebrew kit despertar del cementerio."
I'm guessing that you need to be running 5.50 GEN-B already, can't test it out though cause i've got a 2k1 with an 88v3. :K:
Anyways...
5.50 GEN-B
5.50 GEN-B2