strange crashing behavior

Hi,





One of our users has a very weird problem. When she tries to use ACE, after loading MarvinSketch, if she then tries to move to a new page with MarvinSketch, her browser and system crash.





The particular page that causes her to crash contains frames within frames. If I change that page so it no longer has frames within frames, she no longer experiences any trouble.





The particular page that causes her problems can be viewed this way:





(1) Go here and login as guest, password guest.


(2) Click on ACE Organic Demo Course, click on the Assignments tab, and click on MarvinSketch tutorial.


(3) Click Solve for question 1, enter anything, then move to the next question. After 5-10 times, the browser crashes.





Our user has confirmed this behavior on both PCs and Macs and with several different browsers (Explorer, Firefox, Safari). She has observed it both on computers at work and computers at home. It is not a server load issue, because no one else is using the installation at UK (to which I directed you above). Again, when I change the question-answering page to have just one frame instead of three, her problem goes away.





Another piece of information: When she loads LewisSketch (our own applet) instead of MarvinSketch, she does not experience the problem. So the problem appears to have at least three components: MarvinSketch, too many frames, and particular browsers or Java environments.





Have you ever heard about a problem such as this? Do you have any suggestions on how it could be diagnosed? We're not getting lots of complaints from the field, so there seems to be something unique about her computers -- but she is using several different ones, so it's hard to imagine what that could be. I should mention that she appears to be using quite new browsers and Java versions.





I'm attaching the correspondence with the user. Any help you can offer would be most gratefully received.





-- Bob

:-o strange, I have tried with my Firefox, and works fine. Is it the only course that crashes?

I tried with my Explorer on PC and Safari on Mac, and those didn't crash, either. As far as I know, only one user is having this problem. But she is having it on multiple platforms, multiple computers, with multiple ISP providers. It's really bizarre. Maybe you can look through the correspondence I had with her, and suggest some other diagnostics she might run to figure out what is going wrong?

It is hard to say where is the problem (in Java plugin, in browser, in JavaScript or in Marvin).


Output of Java console and Javascript error console would be useful for debugging.

What should she to get relevant information from her Java console? I had her type m to look at memory usage. Here is her response:





I followed your instructions. I started with the mechanism tutorial,


loaded question 2, typed a wrong answer, hit submit, tried to load


question three and the browser crashed. After the browser crashed, it


won't let me copy anything from the java console. I tried several


times--same results. So, I copied the java console from before it


crashed. Does this help at all?











Java(TM) Plug-in: Version 1.4.2_12


Using JRE version 1.4.2_12 Java HotSpot(TM) Client VM User home


directory = /Domain/uwgb.edu/Users/lukeshj Proxy Configuration: No proxy








----------------------------------------------------


c: clear console window


f: finalize objects on finalization queue


g: garbage collect


h: display this help message


l: dump classloader list


m: print memory usage


o: trigger logging


p: reload proxy configuration


q: hide console


r: reload policy configuration


s: dump system properties


t: dump thread list


v: dump thread stack


x: clear classloader cache


0-5: set trace level to <n>


----------------------------------------------------


INIT SketchPanel


START SketchPanel


Memory: 6.0MB total 3.9MB used


Number of SketchPanel objects (total/live):1/1


JMSketch#927248.run(): loader thread is running


Memory: 8,512K Free: 2,262K (26%) ... completed.

The stack trace and the thread dump would be relevant. Are there any error message on the Java console in the moment of crashing? (If Java console content is not selectable by crashing, taking a snapshot about it can be good to preserve the printed text.)


The memory usage (and the number of SketchPanel instance) is relevant in only that case if the memory usage is abnormally high after the reloading of the applet a few times.

Here is a screenshot of her Java console after the crash. She typed v to get the thread stack. I hope it helps.

Does clearing the Java cache help?


http://www.chemaxon.com/forum/ftopic556.html

No, that was the first thing I suggested. In fact, it's one of our standard suggestions in ACE after you log in.