ATTENTION !!! This personal blog no longer gets new posts

Please follow the official XAF Team and XPO Team blogs, which are regularly updated by me and other DevExpress members.
Thanks, Dennis.
------------------------------------------
In XAF, users of the Model Editor and Report Designer tools are likely to be affected by this issue. Well, advanced users who enabled the ShowPropertyGrid property in the layout control or made custom PropertyGridControl integrations may be affected too - at least we all know a few😉

Our XtraVerticalGrid developers are aware of this problem and have already fixed it in v18.1.4 (it should be out in 1.5-2 weeks). In the meantime, the hotfix is already available for download at T638535: PropertyGridControl - The NullReferenceException is thrown when scrolling and an editor is active. Please accept sincerely apologies from our XAF, XtraReports and XtraVerticalGrid teams for all the inconvenience here.

Here is the error callstack for your reference:

System.NullReferenceException at DevExpress.XtraVerticalGrid.PGEditingState.MouseWheel(DevExpress.Utils.MouseWheelScrollClientArgs) at DevExpress.XtraVerticalGrid.BaseHandler.DevExpress.Utils.IMouseWheelScrollClient.OnMouseWheel(DevExpress.Utils.MouseWheelScrollClientArgs) at DevExpress.Utils.MouseWheelScrollHelper.OnScrollLine(DevExpress.Utils.DXMouseEventArgs, Int32, Boolean) at DevExpress.Utils.MouseWheelScrollHelper.OnMouseWheel(System.Windows.Forms.MouseEventArgs) at DevExpress.XtraVerticalGrid.BaseHandler.OnMouseWheel(System.Windows.Forms.MouseEventArgs) at DevExpress.XtraVerticalGrid.VGridControlBase.OnMouseWheelCore(System.Windows.Forms.MouseEventArgs) at DevExpress.XtraEditors.Container.EditorContainer.OnMouseWheel(System.Windows.Forms.MouseEventArgs) at System.Windows.Forms.Control.WmMouseWheel(System.Windows.Forms.Message ByRef) at System.Windows.Forms.Control.WndProc(System.Windows.Forms.Message ByRef) at DevExpress.XtraEditors.Container.EditorContainer.WndProc(System.Windows.Forms.Message ByRef) at DevExpress.XtraVerticalGrid.VGridControlBase.WndProc(System.Windows.Forms.Message ByRef) at System.Windows.Forms.Control+ControlNativeWindow.OnMessage(System.Windows.Forms.Message ByRef) at System.Windows.Forms.Control+ControlNativeWindow.WndProc(System.Windows.Forms.Message ByRef) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr, Int32, IntPtr, IntPtr)


Tip 1: The How to obtain a design-time exception call stack KB article describes how to locate these important error details, especially if your Visual Studio crashed. This information is helpful when submitting to support. BTW, to improve your chances of getting a faster and helpful answer from support, check these related tips as well:
   How do I ask a good question? (StackOverFlow)
   How to Report Bugs Effectively (Simon Tatham)
   A request for simple example programs (Julian Bucknall)
   Collect and Analyze the Diagnostic Information (XAF documentation)


Tip 2: When you located the call stack information and determined from it that an exception is raised from DevExpress code, I recommend you search for one or several topmost call stack method names in our support database. This behavior might be reported by someone else, e.g.: https://www.google.com/search?q=PGEditingState.MouseWheel

XAF WinForms v17.2.6 - Beware of missing icons in inactive tabs after restoring the Tabbed MDI layout

I want to draw your attention to the T611846: DocumentManager - TabbedView does not show images for documents issue already fixed in the XtraBars Suite and which XAF WinForms Tabbed MDI users might encounter after upgrading to v17.2.6. The number of users who already hit this exceeded a certain threshold, and the known issues section in the What's New documentation or manual searching the Support Center may not help effectively discover it yourself. So, I am posting this here to widely inform those who have not yet upgraded their XAF/WinForms projects to v17.2.6.

You can also download a hotfix build from here.

Please accept sincerely apologies from our XAF and XtraBars teams for all the inconvenience here.

XAF ASP.NET WebForms - Beware of the FormatException (Input string was not in a correct format) when clicking a record in a popup ListView

I want to draw your attention to the T514321: ASPxGridListEditor - FormatException is thrown when selecting an object in a lookup ListView shown from an aggregated collection issue, which is already fixed in XAF for v16.2.7/17.1.4. 

If you came across a similar issue (check the call stack), the highlighted thread contains the hotfix installation for v17.1.

Tip:

When you experienced an exception in DevExpress code, I recommend you locate its callstack and search for one or several topmost method names in our support database, because this behavior might be reported by someone else: https://search.devexpress.com/?q=ASPxGridViewContextMenu.SelectObject&m=SupportCenter

In addition, I recommend checking the Known Issues sections in our What's New documentation:

    all XAF issues that were created in v2016 vol 2.6.

    all XAF issues that were created in v2017 vol 1.3

XAF ASP.NET WebForms v16.2 - Beware of the ArgumentException (An item with the same key has already been added) in Web Dashboards

I want to draw your attention to the T511396: Web Dashboards - ArgumentException - An item with the same key has already been added issue, which is already fixed in XAF for v16.2.7. 

This error can occur if the application model contains different BO Models with the same Caption and is visible in dashboards.

If you came across a similar issue (check the call stack), the highlighted thread contains a simple temporary solution (make captions different or remove the VisibleInDashboardsAttribute from classes that are not required in dashboards)  + hotfix installation.

Web Layout Manager improvements and important changes in XAF v17.1

In the 17.1 version, we have improved the scenario of loading the ASPxPageControl tab content when XafApplication.DelayedViewItemsInitialization equals True and the Conditional Appearance module is involved. So, if you encountered missing or not fully loaded tab contents in this configuration, and had to previously adjust the application-level DelayedViewItemsInitialization or View-level DelayedItemsInitialization options to avoid this behavior (learn more...), starting with v17.1, it is possible to revert these options to True by default. 

Take special note that these improvements required us to introduce some changes, which may affect a very small group of users who created and registered custom layout group templates in WebLayoutManager. Frankly speaking, this was needed for very advanced scenarios (we could locate only a few cases in our large Support Center database), so we expect that the majority of XAF users will not be affected by these changes. Anyway, if you feel or know that you could have been affected, refer to the Web Layout Manager improvements and important changes in XAF v17.1 KB Article for more details.

BTW, have you ever created custom layout item and group templates for WebLayoutManager?:-) If so, please share your use-cases in comments. I am asking because it is quite possible that we already have better solutions for you (e.g., expandable/collapsible layout groups are already supported out-of-the-box)!

The latest XAF v16.2.6 hot fix build for missing collections in the filter editor and a few other issues

I wanted to draw your attention to the subject because the official v16.2.6 contained a few trending issues which were not covered by our automated tests till now:

http://downloads.devexpress.com/Share/DXP/170410/DevExpressComponents-16.2.6.17100.exe

Thankfully, we could provide quick fixes for them and also increased the number of unit and functional tests. Anyway, we apologize for all the inconvenience they might have caused you and your business.

The issues that can attract your attention most of all are:
T500881 - An exception thrown from a popup dialog unexpectedly terminates the whole application execution when debugging in Visual Studio

T498474 - Filter Editor - Collection properties are missing in the property list when DataAccessMode = Server or InstantFeedback after migrating to v16.2.6

Let me know if you experience any difficulties with this hot fix build.

BTW, consider checking the Known Issues section in our What's New documentation if you encounter an issue with our products, because we always inform our customers of such issues + there you can see reports from other clients. I hope you find this information helpful for the future.

XAF ASP.NET WebForms v16.2.5 - Beware of the missing Edit Action after navigating to dashboard items

I want to draw your attention to the T490025: WebEditDashboardController hides the Edit Action of ListViewController and doesn't reactivate it issue, which is already fixed in XAF for v16.2.6. This thread contains a simple temporary solution if you came across a similar use scenario (hotfix installation will be available later).

XAF WinForms v16.2.3 - Beware of exceptions when executing a ParametrizedAction (e.g. FullTextSearchAction) with TabbedMDI and Ribbon UI

I want to draw your attention to the T462973 - RibbonControl - NullReferenceException is thrown in the RibbonItemViewInfoCalculator.CalcEditItemViewInfo method issue already fixed in the XtraBars Suite for v16.2.3 and which XAF WinForms users might encounter after upgrading to v16.2.3. The number of users who already hit this exceeded a certain threshold, and the known issues section in the What's New documentation or manual searching the Support Center may not help effectively discover it yourself. Frankly speaking, we are a bit late with this warning, but it is still better to post this here to widely inform those who have not yet upgraded their XAF/WinForms projects to v16.2.3.

You can find more details and solution instructions in this article.

Please accept sincerely apologies from our XAF and XtraBars teams for all the inconvenience here.

How long since you have seen the "Dictionary already contains ClassInfo ..." error for the Model Editor?

Old XAFers can remember this old sporadic issue caused by a Visual Studio bug that could not be fixed on the IDE side for years (learn more...). We were frustrated by it no less than our users, and this April (15.1.11+, 15.2.8+, 16.1+) we finally found a way to bypass this nasty behavior of an internal IDE assemblies cache on our side by changing the process of  loading assemblies at design time. This was quite a risky change, but so far our testing of many projects under various circumstances went well. We also have not received user reports on the original problem or other side effects with our designers since then (more than 8 months).

That said, I wanted to explicitly clarify with the XAF community whether it is really gone after our changes or not. Please leave a comment below on whether you have seen this error with the latest XAF versions OR you already cannot recall when it occurred last time. If this still bothers you, I would kindly ask you submit a ticket using the Support Center and attach a project where this behavior is stably reproducible, exactly as this kind guy did in the past.

My team and I look forward to hearing from you!