Mismatch or data overflow on MySQL Link Server

[Efthimios Malagrakis]

I try to insert some records to my remote MySQL from my SQL Server. The MySQL is connected as Link server.

The script I run is:

INSERT INTO OPENQUERY(LINKSERVER1,'select virtuemart_category_id, category_name, category_description, metadesc, metakey, CustomTitle, slug, ERPCode from rszcf_virtuemart_categories_el_gr')
(virtuemart_category_id, category_name, category_description, metadesc, metakey, CustomTitle, slug, erpcode)
SELECT AA1, Category_Name1, Category_Description1, Metadesc1, Metakey1, CustomTitle1, slug1, ERPCode1 FROM EGM_WEB_Categories_el_gr T1
WHERE NOT EXISTS
(
SELECT 1
FROM OPENQUERY(LINKSERVER1,'select virtuemart_category_id, category_name, category_description, metadesc, metakey, CustomTitle, slug, erpcode from rszcf_virtuemart_categories_el_gr') T2 WHERE
T2.erpcode = t1.ERPCode1 collate Greek_CI_AI
)

and always I get this error:

The OLE DB provider "MSDASQL" for linked server "LINKSERVER1" could not INSERT INTO table "[MSDASQL]" because of column "category_description". Could not convert the data value due to reasons other than sign mismatch or overflow.

In MySQL the category_description field is VARCHAR(19000) and in SQL Server it is nvarchar(255).

How can I pass this error? Any help?