Large number of updates to Windows 10 last week:
OS Name:                   Microsoft Windows 10 Pro
OS Version:                10.0.10586 N/A Build 10586
Now the Print Centre doesn't work.
Error Details :



ErrorText:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.ArgumentNullException: Value cannot be null.
Parameter name: font
   at System.Drawing.Graphics.MeasureString(String text, Font font, SizeF layoutArea, StringFormat stringFormat)
   at System.Drawing.Graphics.MeasureString(String text, Font font, Int32 width, StringFormat format)
   at Divelements.SkyDemon.Drawing.IndependentText.MeasureText(Graphics graphics, String text, Font font, Int32 width, TextFormattingInformation textFormat)
   at Divelements.SkyDemon.Drawing.GraphicsTable.Measure(Graphics graphics, Font font, Int32 availableWidth)
   at Divelements.SkyDemon.Drawing.GraphicsTable.Measure(Graphics graphics, Font font)
   at Divelements.SkyDemon.Briefing.PlogPrintdocument.DrawJourneyStatistics(DrawingContext context, Rectangle& rectangle, Int32 pageSize)
   at Divelements.SkyDemon.Briefing.PlogPrintdocument.PrintPageCore(DrawingContext context, Rectangle marginBounds, Int32 extraSpace, Boolean& hasMorePages)
   at Divelements.SkyDemon.Drawing.PrintDocumentBase.PrintPageWrapper(Graphics graphics, Rectangle marginBounds, Int32 extraSpace, Boolean& hasMorePages)
   at Divelements.SkyDemon.Drawing.PrintDocumentBase.OnPrintPage(PrintPageEventArgs e)
   at System.Drawing.Printing.PrintController.PrintLoop(PrintDocument document)
   at System.Drawing.Printing.PrintController.Print(PrintDocument document)
   at System.Drawing.Printing.Printdocument.Print()
   at System.Windows.Forms.PrintPreviewControl.ComputePreview()
   at System.Windows.Forms.PrintPreviewControl.CalculatePageInfo()
   at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj)
   at System.Threading.ExecutionContext.runTryCode(Object userData)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme)
   at System.Windows.Forms.Control.InvokeMarshaledCallbacks()

************** Loaded Assemblies **************
mscorlib
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/Windows/Microsoft.NET/Framework64/v2.0.50727/mscorlib.dll
----------------------------------------
SkyDemon
    Assembly Version: 3.4.4.26305
    Win32 Version:
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/SkyDemon.exe
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
Divelements.Aviation
    Assembly Version: 3.4.4.26303
    Win32 Version: 3.4.4.0
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/Divelements.Aviation.DLL
----------------------------------------
Divelements.SandGrid
    Assembly Version: 2.2.4.1
    Win32 Version: 2.2.4.1
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/Divelements.SandGrid.DLL
----------------------------------------
SandDock
    Assembly Version: 3.0.6.1
    Win32 Version: 3.0.6.1
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/SandDock.DLL
----------------------------------------
TallComponents.PDF.Rasterizer
    Assembly Version: 3.0.105.0
    Win32 Version: 3.0.105.0
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/TallComponents.PDF.Rasterizer.DLL
----------------------------------------
System.Configuration
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
Divelements.Mapping
    Assembly Version: 3.4.4.26302
    Win32 Version: 3.4.4.0
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/Divelements.Mapping.DLL
----------------------------------------
Accessibility
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Accessibility/2.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
----------------------------------------
SandBar
    Assembly Version: 1.4.3.2
    Win32 Version: 1.4.3.2
    CodeBase: file:///C:/Program%20Files%20(x86)/SkyDemon/SandBar.DLL
----------------------------------------
System.Web
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.8670 (QFE.050727-8600)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_64/System.Web/2.0.0.0__b03f5f7f11d50a3a/System.Web.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

It looks to me like a required font may have been removed from your system.

No fonts removed by me. I haven't seen anything about Microsoft stopping support for any font.
Give me a clue as to what fonts SD is looking for and where and how to resolve.
UPDATE - just found an item that suggests Windows 10 build 10586 update may be removing fonts that have not been installed by Microsoft products. Is there a way to re-install any fonts that SD requires?

Just tried SD on another Win 10 machine with the smae build and it works fine - but it isn;t my main PC so using it is not a fix. Checking installed fonts between both PC's and the list is identical.

SkyDemon only uses standard fonts that should be installed on all Windows systems.
It's also possible that a printer driver has been changed, or your print settings, resulting in this error. It might be worth checking what printers are installed (if any) and if there's anything unusual about those drivers.

No change in printers. The only difference has been the Win 10 update. Just trying to uninstall one of the Security Updates (KB3124263) that didn't install on the PC that SD works on.
UPDATE - No difference. The only other difference is Win 10 Pro on the PC that SD doesn't work on and Win 10 Home on the one it does work on.

Sorted. The Dymo label printer had been used and the software for that had set it as the Default printer with an odd paper size.
Why is the SD Print Centre sensitive to the default printer for screen view? Surely it shouldn't care until you want to physically print something.

The printing system is invoked in all its glory whenever you view anything, because it's essentially a print preview.

Ok, but surely there could be a more user friendly error message to the effect that you need to change your default printer to one with A4 capability (or whatever doesn't break SD)?

That was only a guess on my part. I wouldn't feel comfortable suggesting that automatically to everyone who experiences an error while the printing engine is running.