Are you currently getting any during the download?
To download Cisco ASDM 7.18, you must access the portal . Because ASDM is proprietary software used to manage Cisco ASA (Adaptive Security Appliance) firewalls, it is not available for public direct download and requires a valid Cisco account with an associated service contract. How to Download Cisco ASDM 7.18
configure terminal asdm image flash:/asdm-7181.bin write memory Use code with caution. Step 3: Launch the New Client