Symptoms:
"Unable to import the vIDM, due to invalid system admin password. Retry after entering the correct system admin password."
As per the error snippet, it is a problem due to account credentials on admin password in VMware Identity Manager, reset the password for admin-HCI and root (make sure it is matching with VCF-lookup_password)
Resetting the admin password on VMware Identity Manager will fix the issue
Follow the Steps as per the article :- How to reset the admin password in VMware Identity Manager