I’ve had similar problems with my WebApps for Xojo. I can debug and everything works fine. But as soon as I use a compiled version the app gets stuck at the loading screen. It works fine in RS but I don’t get to control the scroll positions in WebContainers which makes a few things I’ve implemented impossible to do… 
I have and as you pointed out, WebSessionContext is broken under certain conditions. If you’re to create an app today with what we have today, and not with what we hope to have tomorrow, then what you’re trying to do needs to be approached differently or solved with another tool. If your release timeline is flexible then you have the luxury of just waiting for a fix. It sounds like a fix is in the works and hopefully it will come soon but it is not here today.
Keep in mind that if you fire a method from an event that was fired from say a thread or timer (not web), even if you pass the session around you get session context not available exceptions!!! Even if you create a context on the fly from a passed session that points to the users one.
Also, I hope you don’t wait four months to fix this!!! The quarterly releases are terrible for urgent things like this. None of my projects work on XOJO… I hope you keep this in mind when you set your release cycle for this fix.
Google and Facebook approach is better, they push an update every 3 to 4 weeks NO MATTER WHAT so you can keep working internally to fix things and if the fix or feature misses an update, it’s no big issue since it will be included on the next cycle, if something is broken, you fix it and in less than three weeks its with the users… BUT FOUR MONTHS!!!.. I understand that it was thought that way to make less bugs and rush less, but it has proven to be a bad decision historically because something like this can take months to be fix.
You should at least consider release exceptions for regressions like this… At least that’s what I think.
A paid commercial license should entitle us to better update responses than open source tools.
XOJO is great I just hope that I can use it soon for my projects.
BY THE WAY: take a look at the outstanding bugs in feedback (like not being able to add a subclass of HTTPSocket to dialogs or containers). And my code starts to be a bunch of workarounds more than anything else.
Pleas take this into account when making decisions.
Ps: can you explain exactly what is the bug you determined?
More point releases (focused on bug fixes) between major releases would be nice. Hopefully we’ll see 2013r1.1 loaded with fixes, including one for WebSessionContext.
The original bug was that it was possible for the framework to get the wrong session when WebSessionContext was used by the developer, and the chances went up depending on how many users were connected. This meant that while running in debug mode, many developers would not see the behavior and it would only manifest in a production.
Unfortunately, the fix for this bug completely broke WebSessionContext.
Thanks Greg, I appreciate your response. Hope we can get this fixed soon.
I bought Brad Hutchings’ Web Essentials and it solved the problem completely. Lots of other good stuff in it too.