1. The answer could be pretty simple, there is a big chance that you "my friend" has misspelled the name of the Column somewhere in your code. This is when the Developer Instinct has to kick in. Slow down, and double-check the very column name with an error on. That same column name might very much be misspelled.
2. Go to your SQL Server Table where the column with an error is located, in the "Object Explorer" expand the dbo.TableName, then expand the "Column" folder. Again, Double-check if the column was created in the first place (in the table), if indeed the column was created, then check if it is the same as defined in your code.