I recently had to rebuild an instance of SQL Server.  When it was
restarted, one of the client apps (ASP.NET) could not connect - the
user could see the login screen, but it kept throwing exceptions.
Turns out that the database had been restored with a different name,
so the connection string (stored in web.config) was amended.

At that point the system failed to display even the login screen - it
failed with the error message shown at the foot of this message.

While we were scratching our heads (about 24 hours) the application
suddenly started working again.  For no known reason - i.e. the
intranet server had no changes, no SPs, no HotFixes, nowt.  It just
suddenly decided to play ball again.

Thoughts?

ERROR MESSAGE BEGIN

Configuration Error

Description: An error occurred during the processing of a
configuration file required to service this request. Please review the
specific error details below and modify your configuration file
appropriately.

Parser Error Message: Access is denied: 'Interop.DAO'.

Source Error:

Line 256:                <add assembly="System.EnterpriseServices,
Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/

Line 257:                <add assembly="System.Web.Mobile,
Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/

Line 258:                <add assembly="*"/>

Line 259:            </assemblies>

Line 260:

Source File: c:\windows\microsoft.net\framework\v1.1.4322\Config
\machine.config    Line: 258

Assembly Load Trace: The following information can be helpful to
determine why the assembly 'Interop.DAO' could not be loaded.

=== Pre-bind state information ===

LOG: DisplayName = Interop.DAO

(Partial)

LOG: Appbase = file:///C:/openshare/root/htdocs/cqdb

LOG: Initial PrivatePath = bin

Calling assembly : (Unknown).

===

LOG: Policy not being applied to reference at this time (private,
custom, partial, or location-based assembly bind).

LOG: Post-policy reference: Interop.DAO

LOG: Attempting download of new URL file:///C:/WINDOWS/Microsoft.NET/Framework/v1.1.4322/Temporary
ASP.NET Files/cqdb/8e3a92e1/95733483/Interop.DAO.DLL.

LOG: Attempting download of new URL file:///C:/WINDOWS/Microsoft.NET/Framework/v1.1.4322/Temporary
ASP.NET Files/cqdb/8e3a92e1/95733483/Interop.DAO/Interop.DAO.DLL.

LOG: Attempting download of new URL file:///C:/openshare/root/htdocs/cqdb/bin/Interop.DAO.DLL.

LOG: Policy not being applied to reference at this time (private,
custom, partial, or location-based assembly bind).

LOG: Post-policy reference: Interop.DAO, Version=5.0.0.0,
Culture=neutral, PublicKeyToken=null