Java Crashing "Randomly"

[Gongalong]

Hi folks,

We seem to have a problem with Java, but unfortunately it's proving difficult to resolve.

One of the ICT lessons requires that the students go to the Little Man Computer site, which has a java applet: LMC Simulator

This worked in the previous academic year, but for some unclear reason it's now crashing IE. Oddly it's not crashing for all students, and doesn't appear to be an issue when the local administrator.

Things I've tried without success:

1. Updating Java to the latest version.
2. Removing Ranger.

I deleted the profile for a student where it was working, and subsequent to the profile delete it's now crashing for them as well.

Any ideas as this is rather desperate for an ICT lesson next week?

Plan B is to install Chrome on the required PCs.

TIA

[Duke5A]

Check settings in the Java control panel applet. I've seen issues where Java doesn't pick up system proxy settings correctly, and even had another issue where the temporary cache settings were set too low and causing an applet to crash all the time.

[jonnykewell1]

I think this seems to be the same problem we are having. websites that require java like DL Online - Login , Wordle - Beautiful Word Clouds , Screencast-O-Matic - Free online screen recorder for instant screen capture video sharing. , all seem to cause big problems here.

[themightymrp]

You could also go under the Advanced tab in the Java control panel and enable debugging. You might find something in the output?

[jonnykewell1]

Cheers Phil will have a look =)

[Gongalong]

Duke5A/themightymrp: unfortunately for students it's all disabled through GPO. I've tested with one of the management accounts and Java works without issue.

It's becoming a major problem here because a part of the syllabus is written around Little Man Computer and YouSrc.

One thought is that I'll try removing the sites from our authentication on Smoothwall, if a proxy could be the issue.

[Gongalong]

Tried removing from authentication, and still crashes.

- it doesn't appear to be Ranger
- administrator accounts work with Java
- both staff and student accounts crash IE when launching Java code e.g. Little Man Computer applet

Aaaaaaaaaagh!

[themightymrp]

Do you redirect Application Data via GPO? I've just checked in the Java control panel applet and it wants to save Temporary files to:

%userprofile%\appdata\LocalLow\sun\java\deployment \cache

Perhaps a redirected appdata may be the issue? Or maybe there is a way to centrally managed way to change this location to a folder on the machine which has modified permissions?

[Gongalong]

Yes, we do redirect to the file server. I've inherited the setup so not sure of the implications of changing it?...

[themightymrp]

Does that above folder exist on the redirected appdata share on the server? If so you could try increasing domain user permissions on that cache folder to modify.

When you log in as an admin, can you check in the java control panel where it want to save the temporary files? Does that point to a server share or a local folder?

[Gongalong]

Does that above folder exist on the redirected appdata share on the server? If so you could try increasing domain user permissions on that cache folder to modify.

No, not on the server. I think because this is being stored as local appdata, rather than roaming appdata i.e. Java doesn't support roaming appdata.

When you log in as an admin, can you check in the java control panel where it want to save the temporary files?

It's pointing to C:\Users\username\AppData\LocalLow\Sun\Java\Deploy ment\cache

You can turn off saving temporary files, but it seems to be a user specific setting, annoyingly.

The US$64M question is how can I turn this off on mass? (assuming this is the issue)

[BlueFlag]

Java and Internet Explorer crashing? Bit of a head scratcher, they're both normally rock solid.

[Gongalong]

Certainly hard to pin down.

- it only happens to staff and student accounts
- it doesn't seem to be related to Ranger (with Ranger uninstalled I still get the crash)
- it doesn't happen on administrative accounts (which can see the C: drive in Windows Explorer)
- it doesn't happen in Chrome or Mozilla

Although I'm wondering if your comment is sarcastic now that I think about it :-)