May be this could be the reason of this error, can you check out the below points
Could be that you are trying to insert NULL values in a column that has a NOT NULL constraint or a primary key constraint. You need to provide a valid value for such columns or use a sequence or trigger to generate them automatically.
Check out this link
Could be that you are using an incorrect syntax for SYSDATE function. SYSDATE returns the current date and time as a DATE value, so you cannot subtract another DATE value from it and multiply it by numbers. You need to use proper date arithmetic functions such as TO_DATE, ADD_MONTHS, INTERVAL etc. to manipulate dates.
Check out this link
Can you check column name or table name in your query is correct. You need to make sure that your column names and table names match exactly with the ones defined in the database schema