Two possible reasons why:
1) It's because some stuff has changed in the new Windows Live Messenger. eg: it doesn't support using the internal Messenger API anymore in the way it was possible before.
2) It is because of how Windows 7 deals with ActiveX objects (which is used in this script to call an internal Messenger API). Windows 7 is known to be picky about how ActiveX DLLs are made, handled and called, and not all ActiveX's which worked in XP are Windows Vista/7 compatible. But since the script calls the internal Messenger API (exposed by its own ActiveX DLL), the compatibility issue should not occur since it is made by Microsoft themselfs. This said, the internal Messenger API is also known to have bugs and errors though. So it might be a combination of both...
So, this doesn't have much to do with Messenger Plus! itself, but all with how Windows Live Messenger works now and/or your Windows version.
Aka: the script is still running fine in Messenger Plus! Live itself, it does what it is suppose to be doing, program logic wise that is. It only can't perform the alterations anymore to Windows Live Messenger in the same way it used to.
Such scripts and tools simulate (if you will) the way you would normally add stuff in a manual manner in Windows Live Messenger.
So, if that method changes in Windows Live Messenger or isn't available anymore because the ActiveX object isn't initiated properly or that function isn't supported or working properly anymore, or there are some user rights restrictions in Windows itself, then such tools wont work anymore.
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You could try to re-install Windows Live Messenger, to make sure the Messenger API and the files it needs for that are properly installed and registered.
But other than that there is nothing you can do except for waiting for an update of the
Quick Contact Adder script.
Or use some other tool for mass adding contacts....
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Related and important to know before you proceed:
Why do you want to mass add 700 contacts?
Is it because you changed your Windows Live ID?
Adding all your contacts again to a new Windows Live ID yourself has the massive dissadvantage that all your contacts must again confirm the "
x wants to add you" messages, as well as removing your old Windows Live ID from their contact lists.
And also remember to delete all your contacts from your old Windows Live ID contacts' list first. Otherwise your contacts wont be able to remove your old Windows Live ID from theirs.
Did you know that you can change your Windows Live ID via your Windows Live Profile and that contacts will then automatically be migrated to your new Windows Live ID, without all the hassle of deleting and re-adding? It might not be available for your Windows Live ID, but if it is, it is the way you should be doing it!!
See
CookieRevised's reply to New contact notification! and
CookieRevised's reply to Changed email ID, lost contacts... HELP
Then there is also the method of exporting your Messenger contacts and importing them again via Windows Live Hotmail (it used to be possible via Windows Live Messenger directly, but this isn't so anymore in the newest versions - it's still available via Windows Live Hotmail though).
Both methods are preferred over using the Quick Contact Adder script.
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