Issue
I was trying to import an Excel sheet with cells that contain very long strings (more than 256 characters) to SQL Server through the SQL Server Import Data Wizard.
What I have tried to do
Since the cells contain more than 256 characters, I have changed all varchar’s (or nvarchar) size to MAX. However, it did not solve the issue.
The Solution
Aside from changing the size to MAX, I have transferred one of the rows with a cell that has long strings to the first row so SQL Server would know that, indeed, a particular contains a very long string!
I have read somewhere that you can change something in the registry so SQL Server would automatically treat long strings as nvarchar(MAX), but I haven’t tried that yet.