Increasing the timeout period for ASP.NET
If a web service request runs longer than the default timeout period for ASP.NET, the following message might appear:
Attempted to access an unloaded AppDomain
Such a timeout could occur during synchronization.
To resolve this issue, increase the value for responseDeadlockInterval in the machine.config file on the servers. The default value is three minutes. This is a global value that applies to all ASP.NET applications. For more information about setting the value, see the Microsoft documentation (http://www.asp.net/).
Note: Oracle recommends that you do not change the responseDeadlockInterval value unless you receive the error as described.