@NDH 

Unplug the smart plug and plug it back in so it can resync back to the cloud and try to create the smart action again.

@Tony tried your above suggestion with the HS100 plug, but had no luck.
I want to set my fan to turn on at 6am, so I think the only way to do that is by scheduling a scene in smart actions? If so, when I do it I get this message error even after unplugging the HS100 to allow it to reboot. Help please!!!

@MattK 

You can do that by setting a schedule. Smart action would be if you wanted the plug to turn off after a certain amount of time or turning on one device would turn on that plug too.

Check if you are able to control the plug remotely so turn off your Wi-Fi and test. 

@Tony hithere can't save the scene help please

@andrew2202 

Try re-logging into the Kasa app by going to the top left menu, tapping on your email, logout, and log back in and try to create a scene again.

If you have also not done so, re-install the app as well. 

If you continue to get an error, please post a screenshot of what you are seeing.

I have the same issue.    I have remove the Kasa application from my Andrioid Google Pixel 3A phone.   Rebooted the phone.  Then reinstalled the application from the Play Store.   

When trying to save the smart action i get a pop up stating ":We won't be able to save the smart action at this moment.  Please try again later."

Update:   I just o\installed the Kasa App on a new Google Pixel 4A (it never had the Kasa app installed).     Same error message is displayed

@WSD 

I was facing exactly the same issue.  I realized that I had re-named the plugs after I initially set up the device.  Deleting and re-installing the app itself had no effect on the issue.  Here's how I resolved the issue:

1. I deleted the device - Devices icon at the bottom -> swipe left on device to delete.  I thought it was better for me to delete the device with it unplugged, but in hindsight, I should have left it plugged in.

2. I re-added the device.  Because I hadn't left it plugged in, I didn't reset itself back to factory settings and I had to do that at this step.  I'm not sure whether or not it's important, but I named the devices something different from what I had named them the first time.

3. I removed the previous scenes.  Again, in hindsight, I probably should have done this before deleting the device, but I didn't.

4. I added new scenes, naming them something different from what I had named them the first time.

5. I was able to successfully create and save Smart Actions using the new scenes.

My guess is that something got messed up when I re-named the plugs, which caused issues when the app tried to save the Smart Action with the original names, but it's just a guess.  Something got out of sync, so deleting everything and starting over worked.

Good luck!

@Tony tried failed

@Tony 

Done that, no change, doesn't work. 

@Fergy figured it out. My time zone wasn't set.