Hi, I tested this locally using 8.4 with the settings from your screenshot and I get no such error message. Which version are you on?
The error message gives the example of the clock being adjusted forward that then leads to an issue. What I take from it is that since you selected a time between 2 AM and 3 AM, this is possibly an issue for the system, as "any time in the period that is skipped is invalid". For me that means when the time is changed "forward" in spring to summer time, the clock jumps from 2 AM to 3 AM, making this hour "invalid" for the system as it does not know when to kick off the process.
Can you try a start time after 3AM? 3:10 AM?