Running lastest version: 22.214.171.124
The first thing that springs to mind looking at your ELSE is that it repeats every 7 seconds but you have 8 seconds worth of delays. Your repeat will start again before the delays have completed.
Maybe get rid of the first 2 second delay and repeat every 8 seconds.
That pop error typically occurs when two instances of the same rule are in play by the way. You should do what you can to make sure that you only ever have one instance of a given rule running. So... don't design a long running rule that can trigger very frequently.
It appears to be a very intermittent behavior. The rule is triggered by a VS change transition. I'll keep an eye on logs.