You're missing telling us the DDL of the tables involved.
If you aren't specifying one of the columns in ticket_dump table, SQL Server will try to insert a NULL.
My best guess is that the referred table has more columns than you are
supplying values for. When you perform an INSERT, SQL Server has to have a way to determine a value for ever y column in the new row(s).
You either supply specific values, or you have defined a default value for the column when you created the table, or the column may allows NULLs.
In your case, it looks like there is another column you are not specifying, which has no default and doesn't allow NULLs, so SQL Server can't figure out what value to put into that column. That is why you are getting the error.