Another possible cause of the "invalid field count" error, though probably not on line 1, e.g.
Invalid field count in CSV input on line 250.
is an improperly escaped field separator embedded within a field. One common occurrence is you have a double-double-quote ("") inside one of your fields. Spreadsheets sometimes export a CSV file this way, by escaping a " with another ". So a line might look like:
Nuts & Nut Butter,N270,"Chocolate Hazelnut Butter (""Betony Butter"") *LOCAL* – Case of 12 X 1lb jars",Oregon,,OG ,12.00 lbs,91.2,3
Normally (phpmyadmin import default) the field separator is double-quote ("), and the escape character is backslash (\). So to fix this, you need to change the "" to \":
Nuts & Nut Butter,N270,"Chocolate Hazelnut Butter (\"Betony Butter\") *LOCAL* – Case of 12 X 1lb jars",Oregon,,OG ,12.00 lbs,91.2,3