I did update to latest Windows 10 build 1809 as it officially release today

And I started to see on std output:

Invalid parameter passed to C runtime function.

when I run application with debugger

Step to reproduce:

install windows 10 build 1809 in virtual machine

I used UK location, UK keyboard x64

install qt  minigw53_32 bit

and run network/http example app

with debugger in debug mode

and then you will see many many "Invalid parameter passed to C runtime function." right after app start in Application Output

I can't reproduce with basic widget app

Same in at least this versions

5.11.2\minigw53_32

5.11.2\msvc2017_64

5.11.2\msvc2015_64

5.11.2\msvc2015

5.12.0\msvc2015_64

5.9.6\msvc2015_64