DateTime string parsing throws exception after Unity 2019.1 update

Hi,

i found a strange bug in my game. I updated from 2018.1 (.NET 2) to 2019.1. (.NET 4)
I updated the game over the existing installation on my device.

I have a UserPref string with a DateTime converted to string.
When i try to use

Code (CSharp):

1. DateTime time = Convert.ToDateTime(dateTimeString);

I'm getting a FormatException, the string is not a valid date.

But when i deinstall and reinstall the game this error is gone.
I suspect the DateTime string, saved in player prefs, that was created with the old version of Unity is not readable by the new updated version.

Question:
Did something (in .NET) change that makes this happen in regards to how DateTime strings are parsed in 2019.1?

 

I would assume it is connected to the locales (like in http://www.heikniemi.net/hardcoded/2015/08/windows-10-breaks-net-date-parsing-in-certain-locales/)

 

@kaarloew thanks for the hint, i'll read more about this.