To prevent possible data loss before loading the designer, the following errors must be resolved

Question

_{Monday, May 15, 2017 9:15 PM}

Hi I am getting the following error on viewing the designer for any DAL in my project. Please steer me in the right direction to resolve the issue if you can.

Value cannot be null. Parameter name: instance

Instances of this error (1) 1. Hide Call Stack at System.ComponentModel.TypeDescriptor.AddAttributes(Object instance, Attribute[] attributes) at Microsoft.VisualStudio.Design.VSDesignSurface.CreateDesigner(IComponent component, Boolean rootDesigner) at System.ComponentModel.Design.DesignerHost.AddToContainerPostProcess(IComponent component, String name, IContainer containerToAddTo) at System.ComponentModel.Design.DesignerHost.PerformAdd(IComponent component, String name) at System.ComponentModel.Design.DesignerHost.Add(IComponent component, String name) at System.ComponentModel.Container.Add(IComponent component) at Microsoft.VSDesigner.DataSource.Designer.DataSourceDesignerLoader.HandleLoad(IDesignerSerializationManager serializationManager) at Microsoft.VSDesigner.DesignerFramework.BaseDesignerLoader.PerformLoad(IDesignerSerializationManager serializationManager) at Microsoft.VSDesigner.DesignerFramework.BaseDesignerLoader.Microsoft.VisualStudio.TextManager.Interop.IVsTextBufferDataEvents.OnLoadCompleted(Int32 fReload)

All replies (4)

_{Wednesday, May 24, 2017 7:25 AM ✅Answered}

Hi Daryl Shipman1,

You'd better to check your .config file in your side：

https://stackoverflow.com/questions/5303476/how-to-fix-error-could-not-find-schema-information-for-the-attribute-element

https://social.msdn.microsoft.com/Forums/en-US/6b09be89-c654-4a3b-aff0-858074b2a17a/warning-messages-could-not-find-schema-information-for-the-element-applicationsettings-?forum=netfxbcl

Since it was the web app, you know that it has his own supported forum, if still no help from above links, you could post this issue to the ASP.NET forum here:

https://forums.asp.net/

There you would get dedicated support from the ASP.NET experts.

Best Regards,

Jack

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

---

_{Tuesday, May 23, 2017 7:51 AM}

Hi Daryl Shipman1,

Which kind of app did you create, WinForms or others?

>>To prevent possible data loss before loading the designer, the following errors must be resolved.

To narrow down this issue, you can try to comment out the custom code in your side, sometimes it could help you find much more useful information.

I met this kind of error before which was related to the event:

https://social.msdn.microsoft.com/Forums/vstudio/en-US/2f64b075-29b1-47da-8c60-8249c9ef22fc/windows-form-error-to-prevent-possible-data-loss-before-loading-the-designer-the-following-errors?forum=winformsdesigner

If I have misunderstood this issue, please feel free to let me know.

Best Regards,

Jack

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

---

_{Tuesday, May 23, 2017 9:13 PM}

Hi Jack, thanks for the reply.

I am using web forms in VS Community. I have read the post in the link you gave me thanks, however all DAL.xsd files in my solution wont load the DataSet editor so there does not seem to be any specific code behind error that is preventing the editor from loading? There is however a number of warnings from the .xss please see below. If I open the project in any previous version of VS I can view the DAL DataSet editor without issue. Any help would be greatly appreciated. Regards Daryl

---

_{Friday, October 26, 2018 7:59 AM}

refer the below link

https://social.microsoft.com/Forums/Azure/en-US/13811642-013f-43c8-a483-af079e9e1646/value-cannot-be-null-parameter-name-instance-after-upgrade-to-visual-studio-2017?forum=Offtopic