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Unable to Load iprop.dll

Thread ID:





89446 Aug 24,2009 04:00 PM May 20,2013 05:11 AM ASP.NET Web Forms (Classic) 7
Tags: XlsIO
Whitney Wright
Asked On August 24, 2009 04:00 PM

Hello, I have published my site, and everything working locally but now I am getting an error. Unable to load DLL 'iprop.dll': The specified module could not be found.The sever is a 64 bit, using Windows server 2008 wich does not have a iprop.dll according to msdn. Is there a way I can work around this? I currently have the following dlls.

Geetha M [Syncfusion]
Replied On August 24, 2009 11:43 PM

Hi Whitney,

Thank you for your interest in Syncfusion products.

You can make use the code snippet given below to avoid loading of iprop.dll in 64 bit machines.

application.UseNativeStorage = false;

Please try this and let me know if you have any questions.


Ken Vanderbeken
Replied On September 2, 2009 11:08 AM

I have the same problem. if I add
application.UseNativeStorage = false

to my code i get the following error
BC30456: ''UseNativeStorage'' is not a member of ''System.Web.HttpApplicationState''.

any ideas?

Geetha M [Syncfusion]
Replied On September 7, 2009 03:03 AM

Hi Ken,

You need to set this property at our IApplication interface and not to HttpApplicationState. Please refer the code snippet given below.

ExcelEngine excelEngine = new ExcelEngine();
IApplication application = excelEngine.Excel;
application.UseNativeStorage = false;

Please let me know if you have any questions.


Tyson Ware
Replied On September 10, 2009 04:53 PM


I'm using 7.0 BackOffice and I'm getting the same error when I'm hosting my site on 64 bit server.

I didn't understand putting it at the Iapplication level.

I'm trying to create a new word document.


IWordDocument document;

document = new WordDocument();


Where and how would I put that code snippet. Thanks.

Vijayakumar S [Syncfusion]
Replied On September 15, 2009 06:00 AM

Hi Tyson,

Thank you for using Syncfusion products.

We were able to see the mentioned issue of IProp.dll while using Essential DocIO in 64 bit machine. In our latest source, this issue has been fixed. Could you please post this question through Direct Trac Developer Support System https://www.syncfusion.com/account/login?ReturnUrl=%2fsupport%2fdirecttrac%2fincidents so that we can provide you a solution for this problem and you can take the advantage of the expertise of a dedicated support engineer and a guaranteed response time and we hope you will take advantage of this system as well. Thank you for your participation in Syncfusion’s Community Forums”.

Please let us know if you have any questions.


Esteban Brenes
Replied On May 9, 2013 11:37 AM

Hi, I am using the version in a windows 7 pc, and Im getting this "Unable to Load iprop.dll"error.
I tried to add the line application.UseNativeStorage = false, but that value is not available for the IApplication object I use.


Manikandan M [Syncfusion]
Replied On May 20, 2013 05:11 AM

Hi Tyson,


We highly regret for delay in getting back to you.


The reported issue has been fixed in latest version of Essential studio. We highly recommend you to upgrade your product to newer version.

Download link for latest version:


Please let us know if you need any clarifications.



Manikandan M.


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