Issues I've seen caused at WorldAuthenticate Checkpoint 3 are from CPU being overclocked at > 4.2ghz. Judging by your specs I think this might be the case for you too.
You can use AMD overdrive to setup a profile for P99 to underclock/not overclock beyond 4.2ghz.
Here's a post on the daybreak forums about setting that up.
These threads might give you some more solutions:
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https://forums.daybreakgames.com/eq/...please.212991/
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http://www.eqemulator.org/forums/sho...t=37521&page=4
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http://www.eqemulator.org/forums/showthread.php?t=36707