You can certainly download a new copy of SecureAccess to the flash drive and install it. Whether it will allow you to access the old vault I don’t know. It’s possible the old files are lost and you will be starting over.
Hopefully these links will help you.
https://kb.sandisk.com/app/answers/detail/a_id/2399/
https://kb.sandisk.com/app/answers/detail/a_id/2399/related/1/kw/secureaccess/r_id/101834
