Anyone else got an idea on how to fix this?

Thanks

If you haven't already, try deleting LW's preferences folder when LW's properly closed (check in Task Manager - if there's a LW process running then end the process). See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
This will change all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later. If you have incomplete downloads that you want to resume, make sure to read post #5 of the thread above!
Vista users: LimeWire Pref Folder in Vista

Do you have Alcohol software installed? If so, look here.
LW starts then close, log: resolve_virtual_call

You could also try the advice here: FIX: LimeWire won't start or closes immediately

Thanks for your help, but still no joy.
Still get the error "can't start or initiallize"

What firewall(s) are you using?

Have you updated anything to do with your firewall lately?

What's the brand & model of your modem/router?

Can you temporarily disable McAfee's AV/anti-malware & see whether that makes any difference?

Disabling McAfee did the job.
Thank you for your help.