Need Help With Error Message

I can't see the screenshot can you repost it?

Errors and logs should be text, not pictures. Please read General Publishing Guidelines.

How did you import it from blockbench? Anyway, update your blockbench to latest for no bugs. 

then follow these steps. 

1: Open blockbench
2: Make your model(open)
3: Hit file, project. 
4: Don't use parent, mcreator doesn't have full support yet and it's for advanced modders, just use file name. If entity, use latest mojimaps
5: Name it
6: Save changes. 
7: Save project as first: If you don't, files get corrupted for some reason when you export to mod file
8: Export to file you're wanting. Blocks have obj/html or json. Entities have obj or java only. No others work. 
9: Open Mcreator
10: Go to resources
11: Import java or obj+mtl for entities. Import json or obj+mtl for blocks
12: Follow the guide
13: Enjoy

If that doesn't work, if you're using geckolib, you'll have to go talk to the maker, geckolib has an error with models atm making it incompatible with mcreator. 

If not using geckolib, re install mcreator.