To continue to debug, you must configure IIS to allow the worker process to continue. This error message does not appear with versions of IIS that are older than IIS 7.
To configure IIS to allow the worker process to continue
Open the Administrative Tools window.
Click Start, and then choose Control Panel.
In Control Panel, choose Switch to Classic View, if necessary, and then double-click Administrative Tools.
In the Administrative Tools window, double-click Internet Information Services (IIS) Manager.
IIS Manager opens.
In the Connections pane, expand the <computer name> node if necessary.
Under the <computer name> node, right-click Application Pools.
In the Application Pools list, right-click the name of the pool your application runs in, and then click Advanced Settings.
In the Advanced Settings dialog box, locate the Process Model section, and perform one of the following actions:
Set Ping Enabled to False.
Set Ping Maximum Response Time to a value that is larger than 90 seconds.
Setting Ping Enabled to False stops IIS from checking whether the worker process is still running and keeps the worker process alive until you stop your debugged process. Setting Ping Maximum Response Time to a large value allows IIS to continue monitoring the worker process.
Click OK to close the Advanced Settings dialog box.
Close IIS Manager and the Administrative Tools window.