When you create user accounts in a local vRealize Operations instance, vRealize Operations stores the credentials for those accounts in its global database, and authenticates the account user locally.
Each user account must have a unique identity, and can include any associated user preferences.
If you are logging in to vRealize Operations as a local user, and on occasion receive an invalid password message, try the following workaround. In the Login page, change the Authentication Source to All vCenter Servers, change it back to Local Users, and log in again.