Why does my Easyworship go to sleep if a slide is left up on screen without changing for a while?

That is a Windows setting. Go into the Power Settings and set it to not go to sleep, hibernate, or turn the screen off for the amount of time longer than your services last.

This IS a Windows setting, yes, BUT, as with all programs, this setting can be overridden by how you code the program.  I DO want the computer to disable the monitors after a certain amount of idle time when EW isn't loaded, and I don't want to have to change that every time I load or unload EW.  Take vMix, for example.  When vMix is loaded, the sleep or monitor off time is stopped and vMix does not let the monitors go off or the computer sleep, much like DVD playing apps or WMP or VLC suspends standby timers.  Once vMix is closed, then the timer resets and the screens can again shut off.  You need to look into this because, yes, we have had our stream crash due to the EW computer's monitors going into standby.  It only happens when I start EW way too early and no one is at the PC for over an hour, but it has happened.

EW does not have a setting like this and uses the Windows setting. That is why I worded by reply as such. It appears that you would like to feature request. To do that you need to go to the Feature Request section and post the request there.

But the short answer for now is to either change that setting in Windows or leave a looping video running in a minimized window thru VLC or some other app to prevent Windows from going to sleep. It will take a considerable amount of time for EW to implement that request when (and if) they decide to do so.