Random SkiaSharp exception

Simo_Karjalainen · December 11, 2025, 8:45am

Hi,

We are currently using ThinkGeo version 14.3.1. We are still seeing random SkiaSharp exception on our automation similar to one which Jarno decribed in this old post A random SkiaSharp related unhandled exception

Actual exception is most of the time SEHException but also AccessViolationException is seen:

Exception Info: System.Runtime.InteropServices.SEHException
at SkiaSharp.SKImage.FromPixels(SkiaSharp.SKPixmap, SkiaSharp.SKImageRasterReleaseDelegate, System.Object)
at bkY=.9UU=.9kU=(ThinkGeo.Core.GeoImage)
at ThinkGeo.UI.Wpf.TileView.20U=(ThinkGeo.Core.GeoCanvas)
at ThinkGeo.UI.Wpf.TileOverlay+d__106.MoveNext()
at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Runtime.CompilerServices.AsyncMethodBuilderCore+MoveNextRunner.Run()
at System.Threading.ThreadPoolWorkQueue.Dispatch()

Exception Info: System.AccessViolationException
at SkiaSharp.SKImage.FromPixels(SkiaSharp.SKPixmap, SkiaSharp.SKImageRasterReleaseDelegate, System.Object)
at bkY=.9UU=.9kU=(ThinkGeo.Core.GeoImage)
at ThinkGeo.UI.Wpf.TileView.20U=(ThinkGeo.Core.GeoCanvas)
at ThinkGeo.UI.Wpf.TileOverlay+d__106.MoveNext()
at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
at System.Runtime.CompilerServices.AsyncMethodBuilderCore+MoveNextRunner.Run()
at System.Threading.ThreadPoolWorkQueue.Dispatch()

Do you have any idea what could cause that kind of issue ? Problem is that we cannot re-produce easily since it happens so randomly on automation…

Br, Simo

Ben · December 11, 2025, 2:45pm

Hi Simo,

It seems this exception happens when converting a GeoImage to WriteableBitmap for display. It’s most likely be related to the tilecache, could because of a corrupted tile or a race condition under multi-threading.

Can you locate which overlay which causes this issue, and disable TileOverlay.TileCache temporarily see if it still exists?
what tilecache you are using? Just a standard FileTileCache or a custom one?

And here are something you can do on your side:

Update to the latest version. we’ve made many internal stability improvements that may help, here you can see the change log:
https://docs.thinkgeo.com/products/desktop-maps/changelog/#major-changes-for-thinkgeo-1432
Enable internal logging to capture any underlying issues

ThinkGeoDebugger.LogType = ThinkGeoLogType.Rendering | ThinkGeoLogType.Caching | ThinkGeoLogType.Rendering;
ThinkGeoDebugger.LogLevel = ThinkGeoLogLevel.All;

Thanks,
Ben

Simo_Karjalainen · December 12, 2025, 11:18am

Hi,

Problem with this exception is that it occurs like once in a month or two in our automation which runs lots of tests daily. So disabling cache temporarily would mean that we would need to disable it for months to see if it helps and that cannot be done. Same problem is with the enabling internal logging.

On our basic test setup we have two LayerOverlay’s both using FileRasterTileCache as tilecache. We also have ThrowingExceptionMode set to ThrowingExceptionMode.SuppressException on our overlays but still we get this crash.

Br, Simo

Ben · December 15, 2025, 8:43pm

This issue is fully resolved in the latest beta (052). It only occurred in rare race conditions, and we’ve fixed it at the core level, it shouldn’t happen again.

Simo_Karjalainen · December 16, 2025, 3:04am

Hi,

Great that you managed to fix the issue. Since your next release is going to be on May is there any change to get this fix included to earlier release by somekind of workaround ?

Br, Simo

Ben · December 16, 2025, 5:05pm

I was trying to give you a workaround in the first place based on your current version but failed.

Based on the latest stable version v14.4.2, we can create a hotfix v14.4.3 with this fix.

Simo_Karjalainen · December 17, 2025, 4:05am

Hi,

It would be great if you could create a hotfix with 14.4.3. We are plannig to update our ThinkGeo version after new year so with the hotfix we could get this included as well.

Br, Simo

Ben · December 18, 2025, 1:21am

Hi Simo,

You might want to upgrade to v14.4.2 first, and make sure it works fine with your project. Every issue in v14.4.2 will also exist in v14.4.3.

Thanks,
Ben

Simo_Karjalainen · December 18, 2025, 8:01am

Hi,

Yes, naturally we need to make sure that all other changes between our current version and 14.4.3 are working fine on our application while doing the upgrade.

Br, Simo

Ben · December 19, 2025, 2:07pm

OK. We will do it early next year. Let me know if you find any other issues and we’ll see if we can put them to 14.4.3 as well.

Ben · January 12, 2026, 3:55am

Hi Simo,

We just released v14.4.3, but we didn’t include this change. During testing, we found it could make the peak memory too high. We have an idea to fix both the memory and AccessViolationException, we’ll do it in the beta branch, run more testing, and then bring it into a future stable release once it’s ready. At latest you can have it in v14.5.

Your other request is included in v14.4.3: OgcApiFeatureLayer and LayerOverlay - ThinkGeo UI for Desktop / WPF - ThinkGeo Discussion Forums

Thanks,
Ben

Simo_Karjalainen · January 12, 2026, 4:06am

Hi,

OK, thanks for the info.

Br, Simo

Simo_Karjalainen · January 20, 2026, 4:10am

Hi,

What is the status of that new attempt to fix this one ? Just wondering that would it be possible to get it to coming v14.4.4 hotfix ?

Br, Simo

Simo_Karjalainen · January 26, 2026, 6:03am

Hi,

Any updates on this ?

Br, Simo

Ben · January 26, 2026, 2:49pm

Hi Simo,

Sorry for the late reply. Sure, we will add this one as well.

Thanks,
Ben

Simo_Karjalainen · January 27, 2026, 7:08am

Hi,

Great, Thanks !

Is the schedule “end of the month” still valid for v14.4.4 ?

Br, Simo

Ben · January 27, 2026, 2:34pm

Yep, you will see it within this week.

Ben · January 29, 2026, 5:17am

Hi Simo, v14.4.4 is out.

Simo_Karjalainen · February 5, 2026, 12:11pm

Hi,

This kind of SkiaSharp exception was seen with v14.4.4:

System.Runtime.InteropServices.SEHException (0x80004005): External component has thrown an exception.
at SkiaSharp.SKImage.FromBitmap(SKBitmap bitmap)
at SkiaSharp.SKCanvas.DrawBitmap(SKBitmap bitmap SKRect dest SKPaint paint)
at 9hQ=.RRU=.WBU=(GeoImage image Single x Single y Single width Single height Single canvasWidth Single canvasHeight)
at 9hQ=.RRU=.WRU=(GeoImage image Int32 x Int32 y Single canvasWidth Single canvasHeight)
at ThinkGeo.Core.SkiaGeoCanvas.FlushCore()
at ThinkGeo.Core.SkiaGeoCanvas.EndDrawingCore()
at ThinkGeo.UI.Wpf.AdornmentOverlay.<DrawAsyncCore>d__8.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ThinkGeo.UI.Wpf.Overlay.<DrawAsync>d__65.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at ThinkGeo.UI.Wpf.Overlay.x0U=(Exception e String memberName)
at ThinkGeo.UI.Wpf.Overlay.<DrawAsync>d__65.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ThinkGeo.UI.Wpf.MapViewBase.<DrawOverlayAsync>d__357.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ThinkGeo.UI.Wpf.MapViewBase.<DrawOverlaysAsync>d__351.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ThinkGeo.UI.Wpf.MapViewBase.<ZoomToAsync2>d__288.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ThinkGeo.UI.Wpf.MapViewBase.<ZoomToAsync>d__312.MoveNext()
— End of stack trace from previous location where exception was thrown —
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()

So far this has happened only once and did not happen again when we tried to re-produce it.

Could you please check it ?

Br, Simo

Ben · February 5, 2026, 6:06pm

We are digging in. Is this exception catchable? or it would crash the application?