Currently, if you try to create a topic timer on a topic without a specified timeframe, it’ll just stay the way it is, which can be confusing. So I think it’s reasonable to show an error message when trying to create a topic timer without a specified timeframe.
Seems like a reasonable UX change.
After you click
Set Timer and no time frame is selected we should simply say
Please select a time frame in warning color.
This is now updated in commit