We can't tell you what is wrong with your query unless you show us what the query looks like. It's likely a problem with a missing, superfluous, or mismatched single quote. You should rewrite your code to use parameterized queries. This will make the code easier to read and debug.
Line No 15
Correct this one --> `,'" & TextBox17.Text & "')"`
To this one --> `,'" & TextBox17.Text & "'")`
Line No 24
Correct this one --> ` "'' where Fen_Inovoice_No=`
To this one --> ` "' where Fen_Inovoice_No=`
This not only makes it easier to match textboxes to specific fields but it automatically adds single quotes around fields that require quoting. Note that I replaced "Date" in the query with "[Date]" to prevent a conflict with a SQL reserved word. You can modify your update query accordingly.
You also might have a typo in the field name Fen_Inovoice_No. I suspect you want Fen_Invoice_No