When users rank up after meeting the time requirement the server sometimes lags or freezes until the rank up is complete.

Has this been fixed in a newer build?

I'm not sure, I can't reproduce the issue.

Can you show me your startup log and AdvancedConfig.yml?

Adv config: http://pastebin.com/1fNkCJx1
Log: http://pastebin.com/Lis1ZTWu

Could you try and upgrade to Autorank 3.8.2 if possible?

Sure

Still having the issue, may be linked to #359