Causing ORA errors in a program using JDBC. How to find what’s causing them

The column USER_TAB_COLS.virtual_column = 'YES' indicates if it's a virtual column.

You can get the expressions for each column with:

SELECT * 
FROM user_tab_columns
WHERE data_default IS NOT NULL;

First of all you need to create a directory on the database.

Create or Replace Directory IMP_DIR as 'Path\Path\';

Ensure the user that will import the file has the privilige to Read & Write on the directory (In case you are not using SYS)

GRANT Read, Write ON DIRECTORY IMP_DIR TO user;

Then, include the directory parameter within the import statement

impdp 'sys AS SYSDBA' file=dump.dmp full=yes log=implog.txt directory=IMP_DIR