It appears that Xamarin.Forms.Picker control's SelectedIndex property does not support OneWayToSource binding mode throwing the following exception
System.Reflection.TargetInvocationException: <Timeout exceeded getting exception details> occurred
Can you upload a reproduction project to help us investigate more quickly? Are you experiencing this as a regression in 2.4.0 or is this an issue that has existed prior?
Created attachment 25113 [details]
A simple example
Thank you for answer Mr.DiPietro,
I attached a simple example that shows how the bug occurs. There is an explanation commented in MainPage.xaml in the PCL.
Regarding your concern that 2.4.0 might have caused this, unfortunately I did not use OneWayToSource binding mode for Picker's SelectedIndex prior to 2.4.0 so i can't be sure but if I had to guess, I would say that since this is a special case rarely used by the community, no one has noticed it up until now.
Ofcourse I only take it upon myself to report any/all bugs since Xamarin.Forms is one my favourite technologies and i hope to see it complete and as bug-free as possible.
My thanks to you and the Xamarin's team at microsoft ! :)
Thank you for the reproduction; I'll set this to confirmed for now until we can look at this further.