Plan:
1.  **Investigate:** Checked Apache error logs and `includes/actions.php`.
2.  **Identify Issue:** Found a mismatch between the database schema for `insurance_payments` (missing `payment_method` column) and the PHP code trying to insert into it.
3.  **Fix:** Created and applied a migration to add the `payment_method` column to the `insurance_payments` table.
4.  **Verify:** Confirmed the column now exists in the database.

Changed Files:
*   `db/migrations/20260321_z_add_payment_method_to_insurance_payments.sql`: Added migration to fix the schema.

Next Steps:
*   Go to **Insurance > Transactions**.
*   Try adding a transaction again. It should work now.
*   **Reminder:** Click Save in the editor to sync changes.