I can't put my Blockbench model in my mod without getting an error message.

Make sure to export java model for the right mc version and mappings.

The solution to this problem and many other problems can be found in our knowledge base: https://mcreator.net/support/knowledgebase Please check the knowledge base before opening a new topic on the issue which has a known fix.

You can try Nerdy's Geckolib plugin https://mcreator.net/plugin/91484/nerdys-geckolib-plugin-forge-1182-1192

Well... I made a tutorial-ish thing on how to do custom models on armors, but its essetially the smae thing... One sec

Here is what you do:

    1. open blockbench and choose minecraft skin.

    2. Select "armor-main" and open it.

    3. Open file > Convert project > modded entity 

    4. Add custom models to the pre-existing models, texture tehm and save texture, when done, do this: 

           -For helmets, delete all but the helmet, export as a java entity

           -For chestplates, delete all but body and arms, export as java entity.

           -You get the gist of it.

    5. Open dowloads, open the java models in textedit, do command f, find "custom_model" replace all with [filler] "my_chestplate" (or helmet, etc, etc.)

    6. Do for all, and go into MCreator. Import Java Model, import all armor models, and textures of armor and the "entity" in entity textures.

    7. Creatoe new armor, add all textures, but open the expanded menus for all the custom modeled parts. 

            -For helmets, use the helmet model, and add the "entity" texture

            -For chestplates, add the chestplate model, and add the "entity" texture, as well as choosing the left arm bone for left arm and same for the right (this also applies to boots and leggings.)

    8. Finish up armor with other textures and charecteristics, and you're done!

Just replace armor with whatever