Skip to main content

MSDYN365BC - Publish Extension Error - NetFx40_LegacySecurityPolicy is enabled and must be turned off.

Hi Readers,

I hope till this time everyone would have tried creating and publishing extension on Business Central
on-Prem Version.

If you haven't then start and learn how to do that. If you already started doing this you might be getting an error message while publishing extension.

In this article, we will discuss how to fix NetFx40_LegacySecurityPolicy issue.

Error Message - 

The request for path /DynamicsNAV130/dev/metadata failed with code InternalServerError.
Reason: NetFx40_LegacySecurityPolicy is enabled and must be turned off in the Microsoft.Dynamics.Nav.Server.exe.config file.

To Fix this issue - 

1. Open Notepad as Administrator. 
     Navigate to C:\WINDOWS\system32.
     Right click on Notepad and select Run as administrator.

2. Open "Microsoft.Dynamics.Nav.Server.exe" file from Service Folder as shown below.

3. Change the NetFx40_LegacySecurityPolicy parameter from true to false. Save the file.

4. Restart NAV Service.

5. Try publishing extension again, it should get published successfully.

Hope you find the information useful.

Saurav Dhyani.


  1. Hi Saurav,

    I faced this problem and carried out the steps mentioned in your blog. I am glad it has worked and the NetFX error got resolved.

    Many thanks for posting this.


  2. Hi Saurav,

    Your posts are always helpful. Thank You so much for the valuable info. The error got resolved.

    Thanks once again.


  3. Hi Saurav,

    I do not know where I would be without you. The knowledge that you share is always a huge help!

    Thank you as always.


    1. Thanks KT for the kind words.
      It great to hear that i was able to help.

  4. Hi Saurav there are implications of this change?

    1. I Don't think as this problem does not exist in future versions.


Post a Comment

Popular posts from this blog

Welcome - Microsoft Dynamics 365!

Hi All, In this article we will discuss the new introduced member of Dynamics Family. Yes you heard it correctly, one more new member with Name "Microsoft Dynamics 365" . #ProjectMadeira   #Dynamics365

Send Mail with Attachment From Navision.

Hi all, We have seen how to save a report into PDF and how to send mail to a customer. Let's link these two post in one i.e. Mailing statement to a customer into PDF Format. This article is part of the Series. Please Refer  Table of Content here . If you have the old objects set let me brief you what I will be changing - 

MSDYN365BC - Data Upgrade To Microsoft Dynamics 365 Business Central on premises.

Hi Readers, We have already talked about the number of steps for upgrading to Business Central on Premises from different NAV versions. After that article, I received multiple requests for an article which list down steps for Data Migration. In this article, we will discuss steps of data migration to MSDYN365BC (on-Prem) from NAV 2017. For this article, I am considering a Cronus Demo Database without any customization. For an actual upgrade project, we will have to complete object merge using compare and Merge process. After the Merge Process, the next step is data migration. Let's discuss those steps. Direct Upgrade to Microsoft Dynamics 365 Business Central (on-Prem) is from following versions - 1. NAV 2015. 2. NAV 2016. 3. NAV 2017. 4. NAV 2018.