Emoncms/MySolar Javascript Errors

I have an eight year old local Emoncms/MySolar system running on a Raspberry Pi and integrated display that I use as a real-time monitor for my home PV installation. It’s been bullet proof all that time, running steadity with no OS updates and few updates to Emoncms.

I’m building a new system in the same configuration to replace the old one but with current OS and app software. It runs fine except that I’m getting occasional (once or twice a day) javascipt errors out of MySolar. The errors vary slightly depending on what browser (in kiosk mode) I’m running on the Pi.

With Chromium I get:

localhost says
EmonCMS Error

Message: Uncaught TypeError: Cannot read properties
of undefined (reading '0')
Route: Modules/app/Lib/timeseries.js?v=36
Line:74
Column:48

With Firefox I get:

localhost
EmonCMS Error

Message: TypeError: datastore[name]data[p] is undefined
Route: Modules/app/Lib/timeseries.js?v=36
Line:74
Column:25

In both instances Emoncms continues to run normally but the browser locks up until the page is manually refreshed or the Pi is rebooted.

I’m not seeing this behavior on browsers running on other devices or the Emoncms app running on an iPad (although those don’t run 24/7 like the Pi).

I’m not finding any obvious errors in system or app logs.

This behavior looks similar to that described in this old post, EmonCMS Error with mySolar, which went unresolved.

I’m running current Raspberry Pi OS (Bookworm) and underlying software on the Pi. Emoncms is 11.6.12 low-write.

Any thoughts on what might be going on here and how I might push through these errors would be greatly appreciated.