Liquid error: Error in tag 'section' - 'smk_cart_blocks' is not a valid section type

[Sancho73]

Hello,

I am getting this error    Liquid error: Error in tag 'section' - 'smk_cart_blocks' is not a valid section type on the Cart page.  I am far from a developer and would be appreciated if someone can provide the solution in simple terms.

Thanks

Alex