Piston executed by another fails


Hello, running into a weird issue here and looking for some insight. I have had a setup where one piston will execute another. The second piston itself pauses and resumes a number of other pistons. So the real world version of this is once lux rises above X, Piston A does a number of things one of which is executing Piston B. Piston B pauses overnight lighting pistons and resumes daytime pistons.

This has been working flawless for a bit now. On Friday I updated the webcore smartapp in the ST IDE and now the issue is that Piston B only runs through a few lines. Its supposed to complete 21 actions and stops after the second. The logging shows that it finished its execution stage but it in fact has not. There are no other tasks other than piston related functions so I for the life of me cannot understand why its not completing.

Another note, just hitting “test” on piston B used to trigger and run the whole thing, it does not do that now either.

Snapshots attached. Piston A, line 45 calls for Piston B to be executed

Piston B as shown here and its log;


V0.3.113.20210203 issues

The log shows a recovery event being received by the piston. Those are sent when timed executions have been missed. I don’t really understand a) why it is getting a recovery event, and b) why it isn’t then running the whole piston when it does (in the same way you’d expect a test to).

Is there any logging prior to this?

It is probably worth looking at the Live Logging in the IDE while testing this piston. There could be some errors showing up there that might explain what is going on. Perhaps execution limits or something. Maybe SmartThings have moved the goalposts accidentally or deliberately as they prepare to sunset the legacy platform.


Not at the moment. Whats also weird is that when I press “Test” the piston doesnt even show its attempting to run. It shows the testing piston grey top bar but nothing else, no log entry or anything

So I just had the IDE open and hit the test on this piston, noticed this error in the live logging on ST side;

5:23:06 PM: error java.lang.reflect.UndeclaredThrowableException @line 1329 (api_intf_dashboard_piston_test)

A clue maybe?


It certainly doesn’t sound healthy.

You commented that you updated webCoRE in the IDE. Are you happy that you updated all four of the webCoRE SmartApps (webCoRE, webCoRE Dashboard, webCoRE Piston and webCoRE Storage) and saved and published them all? Might as well start with the integrity of webCoRE itself.


Yes sir, all seemed like it worked well. The previous version of WebCore I had running had the lines commented out when the issue with location mode came up last year or so…

Current smartapp shot out of the IDE;

I do think its on the WebCore side of things just because all of the pistons exhibiting this behavior are identical. There are roughly 8x pistons that rely on others to fire and it appears that they all are having this issue.


I do think that this issue is (for some reason) due to upgrading the WebCore smartapp. Does anyone know how to revert back to a previous version? Searched a bit and nothing really comes up quickly.


Anyone have any more thoughts? The lady of the house is starting to get vocal about the issue so I’ll have to come up with something else soon otherwise lol


So I went back to v0.3.110.20191009 and all my pistons came alive!!!

I will try to make another post with issues I saw on v0.3.113.20210203 because there were a few for me!