Exception calling "SyncElement" with "5" arugments: Index was outside the bounds of the array

Hi folks,

We’re seeing this error pop up intermittently. High Availability setup with 5 nodes, v4.2.21. It only seems to happen once in a while and after an App has been running for an extended period of time. The UI loads fine, but attempting to perform actions will result in many copies of the error being thrown, like so:

I checked out this topic, but I’m not making use of the PSU cache in my case. Index was outside the bounds of the array - Universal Dashboard / Universal Dashboard Help - Ironman Software Forums

If I restart the App, the error vanishes. Thoughts?