Error
Service unavailable
Resolution
This is one of the ever green errors we often used to get
mostly because of service accounts. The common problem will be this account
might not be a member of IIS_WPG group on the server or check IIS_WPG group
have Read & Execute, List Folder Contents, and Read permissions to the Web
site directories. So precheck with a network admin who is creating the service
account for you whether the account has all the required permissions on the
server.
Error
An error has occurred while establishing a connection to the
server. When connecting to SQL Server 2005, this failure may be caused by the
fact that under the default settings SQL Server does not allow remote
connections. (Provider: TCP Provider, error: 0 - A connection attempt failed
because the connected party did not properly respond after a period of time, or
established connection failed because connected host has failed to respond.)
Resolution
Again, there may be several reasons, the most common is checking
if the service account has access to the SQL Server. This error occurs even if
you are not using SQL Server 2005, i.e. the same error occurs even if you use SQL
Server 2000. Similar error occurs if there is any problem in the connection
string too.
Error
It is not possible to run different versions of ASP.NET in
the same IIS process. Please use the IIS Administration Tool to reconfigure
your server to run the application in a separate process.
Resolution
When we host multiple versions of ASP.net in a single server,
we may get this error in event log. The problem might be an application pool will
be associated with 2 different applications that use different frameworks. So
isolating this application into a different App Pools will solve the problem.