In "'CONVERT_COMPLETE_EXPLAIN'" in the file language/en/install.php is a <a> link to the documentation, which links to "3.3" instead of "3.2".
'CONVERT_COMPLETE_EXPLAIN' => 'You have now successfully converted your board to phpBB 3.2. You can now login and <a href="../">access your board</a>. Please ensure that the settings were transferred correctly before enabling your board by deleting the install directory. Remember that help on using phpBB is available online via the <a href="https://www.phpbb.com/support/docs/en/3.3/ug/">Documentation</a> and the <a href="https://www.phpbb.com/community/viewforum.php?f=466">support forums</a>.',