So you are using Kee Vault and KeePass? If so, please try removing KeePass from the equation to narrow down the cause of the problem.
For example, ensure that KeePass is not running anywhere on your computer (including in the system tray or as another user logged in to the computer).
If you can then sign in to your Kee Vault and access to the passwords works as expected, that indicates the problem lies somewhere with the KeePass part of your setup.
Then make sure you’ve gone through all the steps on the Troubleshooting page.
Hopefully that is enough to help you resolve the problem but if not please supply more information about the exact steps you are taking that fail to work and some screenshots of the specific icons and error messages that you then experience.