I posted this question on StaxExchange, and while I received a couple of responses, I'm not satisfied. In the attached very simple code, when WhenEvent is not present, the computation runs smoothly. When WhenEvent is present, which only checks on the time value and does not address values of the dependent variables, the error is generated which makes (to me) no sense. How could the presence of such WhenEvent operator spoil the code in the 1st place ?
Could someone please tell me what is going on.
