Question

Studio Pro error: Object reference not set to an instance of an object

8

Hey there, i keep getting these and similair errors when using basic functionalities in my modeler (on various projects), for example 'find usage' of an element, the adding of some new elements in a page/snippet (adding a new row to a table, for example), and copy pasting certain elements. This happens in both modeler 8.17.0 and 8.17.1 Mendix.Modeler.Utility.Progress.ProgressException ---> System.NullReferenceException: Object reference not set to an instance of an object. at Mendix.Modeler.Common.Usage.<>c__DisplayClass6_0.<.ctor>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Usages\Usage.cs:line 42 at System.Lazy`1.CreateValue() at System.Lazy`1.LazyInitValue() at Mendix.Modeler.Common.UsagesUtil.<>c__DisplayClass0_0.<FindUsagesOf>g__Predicate|0(Usage usage) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Usages\UsagesUtil.cs:line 13 at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext() at System.Linq.Enumerable.<DistinctIterator>d__64`1.MoveNext() at Mendix.Modeler.Common.UsageFinder.FindUsagesProvider.<GetFindResults>g__AddToFindResultSet|6_0(IEnumerable`1 references, <>c__DisplayClass6_0& ) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Find\UsageFinder.cs:line 67 at Mendix.Modeler.Common.UsageFinder.FindUsagesProvider.GetFindResults() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Find\UsageFinder.cs:line 80 at Mendix.Modeler.UIFramework.Progress.ProgressUtil.<>c__DisplayClass2_0`1.<Do>b__0(IProgressInfo info) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProgressUtil.cs:line 50 at Mendix.Modeler.UIFramework.Progress.ProcessRunner.RunStep(Step step) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 98 at Mendix.Modeler.UIFramework.Progress.ProcessRunner.OnDoWork(Object sender, DoWorkEventArgs e) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 71 at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e) at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument) --- End of inner exception stack trace --- at Mendix.Modeler.UIFramework.Progress.ProcessRunner.Run() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 50 at Mendix.Modeler.UIFramework.Progress.ProgressUtil.Do[T](String message, Func`1 action) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProgressUtil.cs:line 53 at Mendix.Modeler.Common.FindResultsControl.PerformSearch() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core.View\Common\Find\FindResultsControl.cs:line 108 at Mendix.Modeler.Common.FindResultsControl.ShowResults(IFindResultsProvider provider) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core.View\Common\Find\FindResultsControl.cs:line 86 at Eto.Forms.Command.OnExecuted(EventArgs e) at Eto.Forms.Command.System.Windows.Input.ICommand.Execute(Object parameter) at Eto.Forms.MenuItem.OnClick(EventArgs e) at Eto.Forms.MenuItem.Callback.OnClick(MenuItem widget, EventArgs e) at Eto.Wpf.Forms.Menu.MenuItemHandler`3.OnClick() at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.Controls.MenuItem.InvokeClickAfterRender(Object arg) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler) Also, when trying to submit this error as feedback, I also receive an error: Mendix.Modeler.Utility.Progress.ProgressException ---> System.ApplicationException: Malformed response: Unknown api version: null at Mendix.Modeler.Main.Feedback.DoSendPostRequest() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Main\Feedback.cs:line 83 at Mendix.Modeler.UIFramework.Progress.ProcessRunner.RunStep(Step step) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 98 at Mendix.Modeler.UIFramework.Progress.ProcessRunner.OnDoWork(Object sender, DoWorkEventArgs e) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 71 at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e) at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument) --- End of inner exception stack trace --- at Mendix.Modeler.UIFramework.Progress.ProcessRunner.Run() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.UIFramework\Progress\ProcessRunner.cs:line 50 at Mendix.Modeler.Main.Feedback.Send() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Main\Feedback.cs:line 46 I have tried rebooting, reinstalling the modeler etc, but the errors keep appearing. Any idea what might be causing this problem?

asked 2021-01-28

Nils de Vries

13 answers

Luuk de Bakker · Answer 1 · 2021-03-04

We are experiencing the same problem in Studio Pro 9.0.4 in our project. I've submitted a support ticket for the issue.

Mendix.Modeler.Utility.Progress.ProgressException ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Mendix.Modeler.Common.Usage.<>c__DisplayClass6_0.<.ctor>b__0() in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Usages\Usage.cs:line 42
   at System.Lazy`1.CreateValue()
   at System.Lazy`1.LazyInitValue()
   at Mendix.Modeler.Common.UsagesUtil.<>c__DisplayClass0_0.<FindUsagesOf>g__Predicate|0(Usage usage) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.Core\Common\Usages\UsagesUtil.cs:line 13
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at System.Linq.Enumerable.<DistinctIterator>d__64`1.MoveNext()

Nils de Vries · Answer 2 · 2021-04-15

Hey there, I received this update on my support ticket

"This is to inform you that the issue has been fixed and the fix is released in Mendix version 8.18.6 and 9.10. Please check and let us know if you face any issues or if you have any questions”

I am not in the position to upgrade at the moment, but maybe this information can be useful to some of you!

Vsevolod Kosminskyi · Answer 3 · 2022-02-08

Hi guys, I have the same issue in 9.10 version.

Seems it`s not fixed yet

Sjors Schultz · Answer 4 · 2021-03-12

Same problem here with 8.17.0. Sometimes this error occur when I copy/paste elements around on the page editor in Studio Pro. Usually ends up in closing and opening Studio Pro, but sometimes I won't get the chance to click X on the popup and then X on Studio Pro because the errors pops up again in a split second. Grrr...

Nils de Vries · Answer 5 · 2021-03-17

Hey guys, a message from Support regarding my Ticket:

“Currently, there is no relevant update on this issue, it is still in progress. I have also asked the R&D team to share an update, once they share more information I will update you.”

I also linked this forum post to my ticket.

Bart Tolen · Answer 6 · 2021-04-14

I had the same error today and found a solution for my specific case. I copy-pasted a list view to another page and the listview did a search by xpath containing '[%CurrentObject%]']

The new page however did not have a dataview. The Modeler does not detect this error and on startup you get:

System.NullReferenceException: Object reference not set to an instance of an object.

Nithish Ravichandran · Answer 7 · 2023-09-19

and so far is there any solution to resolve this issue ?

Patrick Buzzo · Answer 8 · 2024-02-15

We are also experiencing the same error message in 9.24.14. I am curious whether a fix for this will be released soon.

ZeeQue · Answer 9 · 2024-08-13

Getting same issue on 10.13.11 has there been any update ??

César Ramos · Answer 10 · 2024-08-13

Hello,

I'm having this same error, does anyone know how to solve it?

Thank you

Ajay Gopal · Answer 11 · 2024-09-10

I'm having the same error in 10.12.4

Pedro Filipe · Answer 12 · 2024-10-08

I had a similiar Problem. Turned out to be a combo box i moved to another data container.

0 Errors on the console but the project would not run.

I just deleted that combo box, created a new one with the same configuration and it solved the problem.

Syman Scholze · Answer 13 · 2025-04-08

Hi I got a very similar error and managed to solve it by the following procedure:

Remove a page from the app
Try starting the app
1. If it doesn't start, readd the page and delete another one
2. If the app starts, readd the page and proceed with 3
On the page in question remove a widget
Try starting the app
1. If it doesn't start, readd the widget and delete another one
2. If the app starts, readd the widget and proceed with 5
Take a look to all attributes of the widgets, also styles and dynamic classes

In my case I found out that the Label of one widget was referencing an attribute which didn't exist anymore. After I fixed that error the NULL-reference error was gone and I managed to start my app.