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Trial on IISExpress vs. IIS Failing


Hey guys,

I’m trying to setup an internal demo box for our UI/UX guys to get an idea of what integrating the groupdocs interface will look like and running into an issue. Checkout you’ll note it just hangs on loading. I see all the files created in the cache and processing but it never displays on the viewer…

Please note this works FINE running off Visual Studio 2012 and IIS Express - it just bombs in IIS on the server.

You can download the project here (let me know if it doesn’t work):

I’m sure I’m being stupid and missing something - thoughts?


Hello Bryce,

Thank you for your request. We are sorry to hear that you have such issue. We checked your project that you had shared with us, but we cannot reproduce the issue. We tested the project in Visual Studio 2012, IIS Express and IIS and it works fine for us with all these webservers.

Could you please share with us additional information, such as:
1. Your IIS configuration settings
2. Where your web-site is located
3. Does it have write permission
4. What application pool do you use?

Also we checked your application - and we found out that request to the returns an error, but we cannot see it's details. Could you please enable details showing?

To enable the details of this error message to be viewable on remote machines, please create a tag within a "web.config" configuration file located in the root directory of the current web application. This tag should then have its "mode" attribute set to "Off". If you do that we will be able to see your request errors in this application -


customErrors enabled. Here’s the error below as well (I’ll post the config in a separate reply):

Server Error in ‘/’ Application.

        <h2> <i>Value cannot be null.<br>Parameter name: path3</i> </h2></span>

        <font face="Arial, Helvetica, Geneva, SunSans-Regular, sans-serif ">

        <b> Description: </b>An unhandled exception occurred during 

the execution of the current web request. Please review the stack trace
for more information about the error and where it originated in the


        <b> Exception Details: </b>System.ArgumentNullException: Value cannot be null.<br>Parameter name: path3<br><br>

        <b>Source Error:</b> <br><br>

        <table bgcolor="#ffffcc" width="100%">

An unhandled exception was generated during the execution of the current
web request. Information regarding the origin and location of the
exception can be identified using the exception stack trace below.



        <b>Stack Trace:</b> <br><br>

        <table bgcolor="#ffffcc" width="100%">
                  <code><pre>[ArgumentNullException: Value cannot be null.

Parameter name: path3]
System.IO.Path.Combine(String path1, String path2, String path3) +14520374
#FYT.#KYT.#1HY(String filePath, #HYT options) +236
Groupdocs.Web.UI.Controllers.GroupdocsViewerController.ViewDocument(String guid, Nullable1 count, Nullable1 width, Nullable1 quality, Boolean usePdf, Nullable1 preloadPagesCount, String callback) +685
lambda_method(Closure , ControllerBase , Object[] ) +407
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary2 parameters) +261 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2 parameters) +39
System.Web.Mvc.Async.<>c__DisplayClass42.b__41() +34
System.Web.Mvc.Async.<>c__DisplayClass39.b__33() +124
System.Web.Mvc.Async.<>c__DisplayClass4f.b__49() +839035
System.Web.Mvc.Async.<>c__DisplayClass4f.b__49() +839035
System.Web.Mvc.Async.<>c__DisplayClass37.b__36(IAsyncResult asyncResult) +15
System.Web.Mvc.Async.<>c__DisplayClass2a.b__20() +33
System.Web.Mvc.Async.<>c__DisplayClass25.b__22(IAsyncResult asyncResult) +839620
System.Web.Mvc.<>c__DisplayClass1d.b__18(IAsyncResult asyncResult) +28
System.Web.Mvc.Async.<>c__DisplayClass4.b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +65
System.Web.Mvc.Async.<>c__DisplayClass4.b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +51
System.Web.Mvc.<>c__DisplayClass8.b__3(IAsyncResult asyncResult) +42
System.Web.Mvc.Async.<>c__DisplayClass4.b__3(IAsyncResult ar) +15
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +51
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +606
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288


Could you please share with us additional information, such as:
1. Your IIS configuration settings - (password if prompted: Parabola1!)
2. Where your web-site is located - Azure VM
3. Does it have write permission - Yes. I validated that the cache and processing dirs and files exist
4. What application pool do you use? - .Net 4.0 Integrated. 32-Bit disabled. ApplicationPoolIdentity

Let me know if you need anything else.

Kind Regards,


Thank you for your replay and additional information. We rechecked your application after your update. We found out that request to the returns this error -

To resolve this issue and allow access to this folder please fulfill next steps:
1. Open your IIS manager
2. Right click on your web-site -> Edit permissions -> Security tab
3. Add full access for Users group.

If this will not help you, you can also change the identity of your application pool. Change identity to such user or account which definitely has all necessary permissions for “inetpub” folder and all its subfolders.


Ah - that fixed the issue. Thank you for the help! When we get this on a server under an AD domain we’ll have to play around with the permissions so it’s not just a blanket full control to the web user - that’s a bit too much of a security hole. I’ll reply back to this thread if we run into any issues.

Thanks again for all the help.