I almost suspect that this problem only occurs with users who do not use en-US automatically (through Parallels installer) or manually. This could also explain why there are not many more error reports here in the forum and in other sources (Reddit etc.).
The Parallels (Auto-)installer is setting on my system:
	Code:
	PS C:\Users\l3tron> Get-WinSystemLocale
LCID             Name             DisplayName
----             ----             -----------
1033             en-US            English (United States)
PS C:\Users\l3tron> get-WinUserLanguageList
LanguageTag     : de-DE
Autonym         : Deutsch (Deutschland)
EnglishName     : German
LocalizedName   : German (Germany)
ScriptName      : Latin
InputMethodTips : {0407:00000407}
Spellchecking   : True
Handwriting     : False
 So to fix the error it is enough to do this in powershell (administrative)
	Code:
	Set-WinUserLanguageList en-US -Force
Restart-Computer
 It also seems to be no problem to install additional language packs, spell checking, time/date formats in Windows and browsers (e.g. EDGE). As long as the WinUserLanguageList language remains on en-US.