The problem is quite clear, you are trying to read a string typed value as number. Please check the schema and take care all columns are at the right position. You use the build-in Excel component and this component expects you have to map all columns to a schema column regardless if you need it or not. It order of the columns must be exactly the same as the order of the columns in your file (starting with the start column index of course).
BTW: you have posted your question in the Big Data section? Excel are not really Big Data or not?