We currently have 8.5 as our production system but i'm in the process of testing out the new 9.1 release to use as our new production system.
Getting this stack trace when trying to get to the directory*. I might already be logged into it as the login page worked fine yesterday.
Let me know if you need more,
[SecurityException: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security.]
System.Diagnostics.EventLog.FindSourceRegistration(String source, String machineName, Boolean readOnly, Boolean wantToCreate) +810
System.Diagnostics.EventLog.SourceExists(String source, String machineName, Boolean wantToCreate) +315
System.Diagnostics.EventLog.SourceExists(String source) +22
HAP.Web.Global.Application_Start(Object sender, EventArgs e) +93
*directory - Meaning the web link to HAP itself (https://gateway.***.***.sch.uk/extra_test/)
It looks like this error + stack trace is for any page (even setup.aspx). Probably doing something stupid here