Note : I did some tinkering with my Safari extensions and disabled Kaspersky Password Manager extension. I think it might've fixed it. But, my computer still boots like a turtle
I tried restarting my computer and it still boots up slow.
I know what was happening with the "There is no application set to open the URL kpm-agent-product-action:?action=UnlockRequiredNotification;isStartupAction=0"
Kaspersky tries to send you a notification that you need to unlock the vault (UnlockRequiredNotification), but it seems there is some error with it.
For now, the solution is Unlock the Vault.
I hope this bug gets fixed soon.