I just tried creating a small test game with adv3Lite 2.0 using the WebUI and I didn’t encounter this problem, but once I added a third room I started seeing it too. The error messages seem to concern the javascript files that make up part of the WebUI interface rather that adv3Lite, and that’s just material written by Mike Roberts for adv3 which I took over for adv3Lite, so I’m afraid I can’t cast any light on it.
One other thing I did find, though, is that I didn’t get the problem if I compiled and ran the game in two separate steps (clicking the compile icon and then the run icon) instead of one (the compile and run icon).
One other thing you can try, which seems to have improved things a bit in my test case, is editing the t3m file (in a text editor, not Workbench) for your project to move the line -lib adv3LiteWeb up into second position after - lib system and just before -lib webui. According to the TADS 3 System Manual this is where it should be.
I’ve been doing a bit more digging here, and I find I also get random crashes with a WebUI game newly created with the adv3 library. While they perhaps seem a bit less frequent than those I get with adv3Lite, I don’t get a crash every time with adv3Lite. I’m thus inclined to think this must be a problem with the WebUI or with Workbench, rather than specifically with adv3Lite.
This would probably need Mike Roberts to resolve, although, alas, he’s no longer on the scene, unless anyone else is able to shed any light on it.
Failing that, the only other thing I can suggest is that you develop the game using the standard (non WebUI) interface and then convert it to use the WebUI when it’s finished, following the instructions for doing so in the TADS 3 System Manual.