This is so frustrating. I had a previous version that worked fine. I upgraded and i'm havin g the same problems as most on here. I try and launch LW and all i get is the bouncy icon in the dock. I'm running 10.3.3 on my G3 iMac.
There is obviously a major problem with the later versions. It seems they are not intent on fixing the problem.
I've tried fixing permissions etc and i don't reallty want to go back to a OS9 version.

i feel sorry for the Mac OSX users who have gone for the pro version.

I've downloaded java 1.4.1 first and then 1.4.2 (it won't let you do 1.4.2 straight off) and i can confirm LW is working perfectly. looks like this is the problem, Java update. I'm running 10.3.2

I've had this issue with other apps. Problem is I can't remember how I remedied it. (1) 1st, try restarting yor computer. (2) Repair permissions if that doen't work. (3) Uninstall & try again!
In OS9 you could rebuild your desktop & in many cases everything would be hunky-dory. But in OSX, it's not so simple despite the problem is probably somehow related. I do know that a week/so after this happened the app would mysteriously open fine.

It's strange how the recent version works for some people but not for others. I've noticed this has been the case for a no. of versions that have been released.
The suggestions I can make are (reiterating a little):

1. (a) Make sure you have the most recent version of Java. (b) Try the Standalone Java installer because installing over the net can cause side fx.

2. Do a (a) Safe Mode start & (b) Repair Permissions, & then check with (c) Disk Utility & fsck, & if necessary run all other mac & 3rd party utilities (eg: DiskWarrior, Norton Utilities & AV, TechTool Pro) on your computer.

3. Uninstall LW completely (do a complete search to make sure you have trashed every single LW item incl. prefs. - though you could move the incomplete files including download.dat & bak somewhere else temporarily.) Then reinstall.

4. Try out the LW Beta version (Pro users will find download link at bottom of their personal dwnld page)

5. Install in a new admin user account to isolate a home account problem

6. Go back to earlier version of LW until a new update comes out.

7. (a) Be radical & start completely over by reinstalling OSX & updates & then LW (as last resort only.) (b) Else, & probably 'preferable' is to install the Apple Combo Standalone installer. Updating over the net can sometimes cause issues so using a standalone installer & in one installation hit such as the combo seems to overcome some of those issues.

8. Try the Jum Build which is a beta (more experimental than the regular LW beta) but easier to install.

All these suggestions have worked! But they don't all work for everybody. One of them should/will!

6. Sometimes a new version doesn't work as well on a particular person's set up than the previous version they were using. This usually applies to windows users. But the newer versions are supposed to connect easier & are more ram stable (don't use quite as much ram.) There's also other additional improvements. Stick with LW 4.2.3 for now.

Did you install BSD when you installed 10.3.5? It 'should' be installed to give LW full support. I'm not sure about OS 10.3.x installers but certainly in the earlier installers you could choose whether to install it or not.

1. Try installing from the Standalone Java installer found here: Standalone Java installer (Click on link) Sometimes installing directly from online seems to cause some issues. That's why I'm recommending you to install from the standalone installer. This may oversome some problems with your initial Java installation.

2. (A) Restart in SAFE mode; hold down the SHIFT key immediately after the computer restarts & keep held down until you see the message booting in safe mode. Go to menu bar & select Utilities folder. Choose Disk Utility. Repair Permissions on OSX. Restart computer & try again with LW. (B) If still the same problem, then find your OSX startup disk & place it into the comp. Restart comp whilst holding down the 'c' key. This will force the comp to restart from CD/DVD. Find & Open Disk Utility on startup disk & choose Repair Mac OSX. Quote from Apple website: Steps for using Disk Utility:
1. Insert your Mac OS X CD-ROM disc or Restore DVD disc, then restart the computer while holding the C key. 2. Once started up from CD or DVD, choose Disk Utility from the Installer menu. Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from disc to access Disk Utility. 3. Click the First Aid tab. 4. Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions. 5. Select your Mac OS X volume, if necessary. 6. Click Repair.

Step 5 would be best explained by Stief. It means you can create a separate user & log-in account so that you're almost using LW on virgin territory so to speak.

Sorry to hear you're having problems with LW. But with any luck we'll be able to get you up & running. LW is the best p2p app for mac. You can connect with other p2p apps as well on the Gnutella network.

(To kill 2 birds with one stone.) Also can you tell us about your connection setup? Just in case of potential issues: What brand name & model number of modem & router do you use? Do you use a firewall? Are you connecting from work/home? Some dsl/adsl modems/routers use NAT (as does Apple's airport) which blocks most incoming ports in a similar fashion to a firewall. If you use such a modem we can forward a port for it. A quick check is if you visit this site (ignore the text in the red box) & tell us what it says in the grey box underneath 'The Applet': All I need to know is what's probably on the 4rth line & it says about NAT (eg: It would appear that your machine does use NAT.)

They are not updaters. They are only refered to updates. They are in fact the main program. If problems installing then follow the above suggestions or go to OSX>Library>Receipts folder & view in list mode. Then delete any old LW versions listed. Then try to install. This same principle also applies to the Standalone Java installer. Sometimes the OS says it's already up to date ... so you dump the Java from the receipts folder.

OK. Not sure the reason for your issue. But sometimes having the receipts package of the same file & version of file will stop installation. As you mentioned a Null error.

Reinstalling Java or OS Combo often fixes the bouncing in dock problem.

I just installed LW Pro 4.0.7 (same problem happened with free version earlier) on to Mac OSX Panther 10.3.4 and despite trying to download with Safari, then Explorer (with full deletions of all LW files and safe booted permission resets in between) and 4 attempts at installation, the program will not launch. The application icon bounces in the dock then vanishes after about 1 minute. Any suggestions?

Thanks for the suggestions but I had already tried those manoeuvers! I finally downloaded the OS9 version and it seems to run well under Classic, but it's a primitive workaround.

I've been running Java 1.4.2 the whole time!