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After the upgrade you will need to configure authentication handling and and make any adjustments required for advanced use (see Configuration), but authentication and UI considerations are typically the main thing you'll need to deal with to get things going and get back to a working system. While there are strong parallels provided to what came with V2 (JAAS-based form login and RemoteUser-based authentication), there are key differences that have be accounted for in many cases:
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