We are running an asp.net app (v4.0) and under all operating systems apart from windows 10 it works perfectly, but on Windows 10 the date format lists as en-us (as opposed to en-gb) - this causes an issue parsing the date.

If we run the webs server as an application under comparability mode (Win 8) it works fine too :-/ (though it would appear the service ignores any comparability mode settings so this isn't a solution)

If we run the web app on windows 10 under IIS it also works fine.

We have replicated this on a number of machines (all of which have Windows 10 creators edition loaded)

Has anyone else come across this or got any thoughts? Even if not i hope this post may save someone hours of work identifying the issue if they see it!

Regards

patrick

Yes, under IIS its fine and if we run UWS as an application in compatibility mode (Windows 8) its also fine.

As summary, same application/database in all cases

Windows 8 - no problems
Windows 10 in UWS in Windows 8 compatability mode - no problems
Windows 10 native mode IIS - no problems
Windows 10 native mode UWS (or service) - problems


We inserted logging in the App/handlers and we can see the nationality code change....on the same machine in and out of compatibility mode, similarly IIS on the same machine no problems.

We have replicated on more than one Windows 10 machine, but they ARE all running creators edition (not sure if that's significant or not!), but i would suspect it may be as I would be amazed if we hadn't run this same function on a previous build of Windows 10 under UWS, but I cant guarantee that....

Hi I think we have solved this!

Essentially it seems to be down to the way Windows 10 delivers the country information (that differs in compatibility mode) - we assume a shim is applied to use a different method.

If the machine has been built in US format originally (as per anything from Dell etc!) the service account country code are set to US and UWS picks this up.

In order to fix this :

Control panel/ time and language/region and language/ additional date, time, & regional settings/region/administrative tab/copy settings button/tick all options/ OK

This copies the regional settings from the current account to ALL other accounts....

Reboot machine

We would assume this might affect anyone who is running in non US date format.

As IIS doesn't seem to suffer the same fate we assume Microsoft either use a different method originally, or have silently fixed the issue in IIS.

Hope this adds to the collective knowledge and saves someone else some head scratching!