Input string was not in a correct format (3.80 to 3.90)

I have exported the products from nopCommerce 3.80 in Excel format, opened it in Excel and deleted 3 columns with headers named SpecialPrice, SpecialPriceStartDateUtc and  SpecialPriceEndDateUtc that are not in use in 3.90 version.
Added 2 new columns in the correct position in the Excel spreadsheet, ProductAvailabilityRange and ProductTags respectively.
So the two spreadsheets have the exact same column headers name and position.
When I try to import it in 3.90 receive the "Input string was not in a correct format" message.
The both spreadsheets have 94 columns after the edition, before the one of 3.80 have 95 columns.

What I lost?

I discovered whats going on: You can't export products with attributes from nopCommerce 3.80 to  the 3.90 using Excel.

leodemario wrote:

Correct..You need to do an in-place upgrade of your 3.8 database.  Import/Export functions only work within the same version of Nop.  Between each version of Nop, there is usually new attributes added to Product entity or new relationships that prevent it from being possible.

Thanks ChuckR,

Best Regards.