We ran into an issue during CRM outlook installation where installation was completed and during the configuration of organization, it returned the below 2 errors (from log file).

Error| Error connecting to URL: https://CRMServerName.crm.dynamics.com/XRMServices/2011/Discovery.svc   Exception: Microsoft.Crm.CrmException: Logon failed due to missing credentials at Microsoft.Crm.Outlook.ClientAuth.PassportAuthProvider`1.SignIn() at Microsoft.Crm.Outlook.ClientAuth.ClientAuthProvidersFactory`1.SignIn(Uri endPoint, Credential credentials, AuthUIMode uiMode, IClientOrganizationContext context, Form parentWindow, Boolean retryOnError) at Microsoft.Crm.Application.Outlook.Config.DeploymentsInfo.DeploymentInfo.LoadOrganizations(AuthUIMode uiMode, Form parentWindow, Credential credentials) at Microsoft.Crm.Application.Outlook.Config.DeploymentsInfo.InternalLoadOrganizations(OrganizationDetailCollection orgs, AuthUIMode uiMode, Form parentWindow)

Error| Exception : Culture is not supported.

Parameter name: culture 0 (0×0000) is an invalid culture identifier. at  Microsoft.Crm.MapiStore.DataStore.WaitInitialized()   at Microsoft.Crm.Application.Outlook.Config.OutlookConfigurator.InitializeMapiStoreForFirstTime() at Microsoft.Crm.Application.Outlook.Config.OutlookConfigurator.Configure(IProgressEventHandler progressEventHandler) at Microsoft.Crm.Application.Outlook.Config.ConfigEngine.Configure(Object stateInfo)

Initially i followed the article: http://social.technet.microsoft.com/wiki/contents/articles/5727.microsoft-dynamics-crm-outlook-installation-issue.aspx
and gave user level permissions on the User settings entity but this didnt solve the problem. I had to give Business Unit level write permissions (which is the minimum possible) on User entity to fix this error. Below is the screenshot of the security role which resolved my issue: