NB. This problem has now (1 Aug 98) been fixed with a new wired-classes.zip Java archive. It should no longer be neccessary to apply the fixes described below.

Running WIRED with Netscape 4.03 to 4.05 on Windows 95/NT

WIRED crashes when run in Netscape 4.03 to 4.05 in Windows 95/NT. This is due to bad interaction with the later versions of the JIT ("just in time") compiler. This problem also occurs if you are using a JDK1.1 version of Netscape (ie. 4.03-4.05 with the JDK patch, or 4.5), but those versions anyway work properly with the new version of the Event Display.

There may be similar problems in Windows 3.1 (I haven't tested this). If so, only option (3) should be attempted.

Symptoms

When running the old (JDK 1.0) version of the event display, Netscape 4.03-4.05 displays everything (title, links, control buttons, and black image area), but the black image area remains empty and there is nothing to roatate or zoom. You can verify that this is a crash (and it's not just a very slow link) by activating the Communicator|Java Console menu option. The crash is indicated by the messages

DoAction failed: java.lang.ArrayIndexOutOfBoundsException in View
Thread died...
java.lang.Exception: Stack trace

at the end of the console log.

Workarounds

There are a number of different ways round this:-

Use the plug-in version of the Event Display. This is probably the simplest option, if you don't mind the download time and sightly slower operation. This method has no impact on other Java applets (though the following methods shouldn't cause problems).
Replace the JIT compiler with one that works: download jit3240.dll (from Netscape 4.01) and use it to replace Program\Java\Bin\jit3240.dll (below your Netscape directory, usually C:\Program Files\Netscape\Communicator). You may want to save the old version before doing this (if you forget to do this and want to restore the original file, here are copies of jit3240.dll from Netscape Communicator versions 4.03, 4.04, 4.05). If you have run any Java applets (eg. attempting to run the Event Display), then you will need to restart Netscape before Windows will allow you to replace jit3240.dll.
Do not attempt this if you are using a JDK1.1 version of Netscape (ie. 4.03-4.05 with the JDK patch, or 4.5) - in any case those versions work properly with the new version of the Event Display.
Disable the JIT compiler. This method has the advantage of requiring no further downloads. Move, rename, or delete the file Program\Java\Bin\jit3240.dll (below your Netscape directory, usually C:\Program Files\Netscape\Communicator) eg. rename it to jit3240-save.dll. NB. If you have run any Java applets (eg. attempting to run the Event Display), then you will need to restart Netscape before Windows will allow you to move jit3240.dll.
You can confirm that the JIT has been disabled with Communicator|Java Console. Normally Netscape 4.04/4.05 shows
```
Netscape Communications Corporation -- Java 1.1.2
Type '?' for options.
Symantec Java! ByteCode Compiler Version 210.065
Copyright (C) 1996-97 Symantec Corporation
```
(or Symantec Version 210.057 for Netscape 4.03). With the Symantec JIT compiler disabled, only the first two lines are displayed. Without the JIT compiler WIRED (and other Java applets) won't run as fast.
Install the previous version of Netscape, 4.01. This may be obtained from the Netscape Archive: Windows 95/NT options are: base install (8 Mb), with components (13 Mb), or Professional Edition (15 Mb). There are only minor differences between Netscape 4.01 and 4.05, so you probably won't notice the difference otherwise.

Having updated (maybe that's downdated!) Netscape or Netscape's JIT component, the Event Display should now work. If you have any trouble with all this, feel free to contact me for help.

Navigation links: [Event Display main page] [RAL Particle Physics]

http://hepwww.rl.ac.uk/WIRED/native-1.0/hacks.html last updated on 1st August 1998 by

Tim Adye, <T.J.Adye@rl.ac.uk>