The variable 'e' is declared but never used

Dereference of a possibly null reference.

Cannot convert null literal to non-nullable reference type.

Dereference of a possibly null reference.

Dereference of a possibly null reference.

Non-nullable field 'serial' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'dbcc_name' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'dbcc_classguid' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.