Hoping someone can shed some light on this.  We recently moved a DNN 06.01.05 (142) install from a dead server to a new one.  This is an internal employee portal we have been running for years without issue.  All appears fine on the new server but users get an error on the first time users open the site each day.

Users then close and re-open the site, and if the had logged in the previous day then they show logged in status.  If not they can login using the standard login page.  So if the user was logged in the prior day they now they show as logged in and they have no issue closing and re-opening the site.

When a user does login this is the page they get, they select Windows login, use their credentials and all is well.

I see this error on the login page now, do not remember on the old server.  Windows login works fine and the site keeps state when closing and reopening (timeout set to 10 days).  But every day the users open and get the above 500 error.  If the close and re-open they are logged in and all appears fine.  Now myself and my network admin do not have this issue so permissions seem to be in play - site is internal and security open to everyone for testing, still no change.

thanks in advance.