Could not load file or Assembly '.. ' or one of its dependencies. - Add a blank space on web.config back to work for hours

Question

I have an administrative panel made in webform Asp.net C#. For a few days now, it started giving problems of the type

Could not load file or assembly 'chat_megacorretor.dll' or one of its dependencies. The system cannot find the file specified.

The system crashes, but all I have to do is open the web.config to add a blank space and the site goes back to work for hours, but then automatically crashes again.

Simply rename the file and go back to the original that works again, or upload the project file to the server. I know that when I do this the ASP.Net recompiles everything and so it works, but after a few hours to again.

This same project worked for months, and now it started to give problem, recently we did a reinstallation of IIS from scratch, but I do not think that is the reason, because after the reinstallation worked for a couple of weeks. But now it’s started giving trouble once again.

In the Event view I can’t find anything interesting, just a few warnings.

That I don’t even know if they refer to that problem in itself:

Exception information: 
    Exception type: ConfigurationErrorsException 
    Exception message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level.  This error can be caused by a virtual directory not being configured as an application in IIS. (C:\inetpub\wwwroot\megacorretor\siga_2008\web.config line 16)

and also:

Process information: 
    Process ID: 12680 
    Process name: w3wp.exe 
    Account name: IIS APPPOOL\admin_Net 

Exception information: 
    Exception type: FileNotFoundException 
    Exception message: Could not load file or assembly 'CHAT_Megacorretor, Version=1.0.0.0, Culture=pt-BR, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.
   at Siga_2014.admin.Admin.DefineChatsWMB(Cliente iCliente)
   at Siga_2014.admin.Admin.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)

Answer 1

This problem is related to . dll CHAT_Megacorretor, Version=1.0.0.0, Culture=pt-BR, PublicKeyToken=null undetected.

Review the settings for pool which is linked to its application. Perhaps the pool application may be being recycled at wrong times, or the "Fault Protection" settings of pool application, may be causing failure.

UPDATE

What occurred to me now is that the problems may also be related to your . dll version, if your . dll (Chat_megabroker) is not in the GAC, but directly in the folder along with other . dlls and you updated the site, though, did it without for the pool. Reference problems may occur. Try to stop the application pool, delete all application files and republish it.