Mod not working

Hi. Today I updated my MCreator version from 1.9.0 to 1.9.1. I was using a workspace in 1.9.0 and now I am using it in 1.9.1. I made some updates and added things, and when I test it in Minecraft, it appears in the mod list, and I can see all of the information, but when I open a world the mod plants and structures don't spawn and the items and block don't appear in the inventory. I don't know if it is because of the change of the version or of the content I added. Could you help me?

Thanks.