Unable to save a piston - Resolved


When I save a piston it looks like it is saving but then just goes back to Edit, not back to View piston. If I then exit Edit, my change has not been saved.

I used Community Installer to update webCoRE a couple days ago, but it was strange that CI says the latest version is 0.2x but my SmartApp code says 0.3x. Maybe I downgraded somehow?


This usually happens to me when I attempt to save a fairly large piston. The “chunk-count” will increase to 18-23… then hang… then the piston goes back to edit. (unsaved)

If this scenerio sounds familiar, you can try tidying up the piston to conserve a bit of space…

A pro tip (for future reference):
We can also clear the log at the bottom, which will open up a bit more memory for saving a complex piston.


Thanks for the quick response. I should have said that it’s happening to all of my pistons. The particular one that I’m trying to change is a 2-chunk piston.


I don’t think I have ever had that happen on a smaller piston…

My first thought is to clear the browser’s cache, or test using a different web browser.


@WCmore, thanks again for assisting.

It happens both on a mobile browser and on Chrome on Windows.

I do see these errors in the SmartThings log:
java.lang.reflect.UndeclaredThrowableException @line 1760 (listAvailableDevices)
java.lang.reflect.UndeclaredThrowableException @line 1166 (api_intf_dashboard_piston_set_save)

Do you think I have something wrong with the SmartApps’ versions?


Tagging @ipaterson


@BartschLabs Did you get resolved? I am facing the same issue.


Hey @R34220, I did get it resolved yesterday. Turns out I’ve had this problem before in March 2021 and forgot about it. The answer is here: Unable to Save New Piston