Why am I getting a converting data type error when selecting a decimal column?

I am trying to SELECT a column from a view as shown.

The datatype of the column is stored as a decimal(18, 7), null.

SELECT DecimalPercentageColumn 
FROM dbo.DetailsView

However when I try to do this an error message is returned:

Msg 8114, Level 16, State 5, Line 1
Error converting data type nvarchar to numeric.

via Chebli Mohamed