As discovered by one customer with Confluence and SQL Server, it is possible for the lock escalation issue to affect user login.

Confluence will hang as soon as the second user tries to login. Admin user that tries to access the admin panel will also make Confluence hang as they are prompted for password to access the panel.

The customer was using legacy jira user management

Known workaround

Setting the isolation level of the database as follows is known to fix the issue:

ALTER DATABASE <database name>
   SET READ_COMMITTED_SNAPSHOT ON
   WITH ROLLBACK IMMEDIATE;