How to Triage Web App Caused Freeze in IE6 Mobile on Windows Mobile 6.5 Pro

Question

I have a web app that appears to be causing the device to freeze up. This web app has been working fine for about a year. What changed:

1. We then tried adding an for a windows media player control so we could play sounds on different events.
2. This also introduced a periodic AJAX call to check for the events to play the sound.
3. About the same time we upgraded JQuery to 2.0, then realized it doesn't support the older IE6 browser, and so rolled back to JQuery 1.9.1

What happens? If the user sits on a single screen for 2 hours or so, IE freezes up and they have to reboot the device (Honeywell Dolphin 6000). If they are navigating around it seems this delays the time before the freeze, but inevitably it too will freeze.

Originally I thought this had to do with the periodic AJAX calls taking up memory with each call to the point of a freeze. But we have removed point 1 and 2 above. So I am stumped as to what would be causing this.

Running the app in IE 11 and running in IE5/Windows Phone emulation mode, I get no errors, and can verify with the network profiler that no AJAX calls are being made.

The users usually (9 times out of 10) don't get any error messages...the device just freezes. Once they got a iexplorer.exe has crashed error with the option to send the details to Microsoft.

I tried running the app in IE 11 in Edge mode and doing a Memory profiler and the memory use stays consistent. It is around 173MB, which seems high but I'm not familiar with this to know. The Heap size is only 1.81MB.

Is memory the main issue that causes a device to freeze? What other culprits are there? How do I even begin to triage this?

Answer 1

Turns out it was JQuery 1.9.1 that was the issue. Once I downgraded it further to 1.7.1 all the freezing issues went away.