Error MessageReasonResolution

Input string was not in a correct format.

A required column's data is not the required format - usually a number.  Import data may be blank or contain alpha characters or symbols such as commas, currency symbols etc.Remove the data that is not in the required format.  Replace blank data with a zero.
'System.Dynamic.ExpandoObject' does not contain a definition for 'xxxxxxx'
You are missing a required column/header in the import spreadsheet.  Even if you do not need to populate it with data, it still needs to be included in the import.The message will contain the missing header name that needs to be added to the import spreadsheet.  eg: does not contain a definition for 'AccountCode' where AccountCode is the missing header
String was not recognized as a valid Boolean.
IsActive column missing TRUE or FALSE valueAdd TRUE or FALSE to IsActive column.
Method arguments are not valid! See ValidationErrors for details
Missing required/mandatory data.Check the fields required for import and populate with valid data.
No code specified.
No product code/sku data in required/mandatory columnPopulate the code/sku column for each row.