Wrong parameters: line_items

I’m getting this error over and over:

{“code”:”rest_invalid_param”,”message”:”Par\u00e1metro(s) no v\u00e1lido(s): line_items”,”data”:{“status”:400,”params”:{“line_items”:”line_items[0][price] no es del tipo number.”}}}

Could you please help me fixing this? I can’t find nothing to fix it in the code.

Thanks in advice.

Cheers!