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We recommend all users of 1.6.x upgrade to this version. The 1.6.3 database is compatible with v1.6.0/1.6.1/1.6.2, so rolling back your installation in the case of errors is trivial.
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Core Modules
This release includes version 0.5 of the Logic module as a core module. You may upgrade this module, but you may not remove it or downgrade it below that level.
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