Could not figure out how to reopen bug. This bug is already entered as #008846 but marked fixed.

forum_topic.tpl has some strange math. $page_limit=20 but for first page $reply_limit=19, the idea probably being that original topic plus 19 replies make 20. However if 20th reply is entered, which should show on second page, then navigator/google.tpl calculates:
page_count=int( ceil( div( $item_count,$item_limit ) ) ), in this case int( ceil( div( 20,20 ) ) ) -> 1
and link to second page is not shown.

Simple fix: in forum_topic.tpl, set:
{let page_limit=20
reply_limit=20
reply_offset=$view_parameters.offset

Nobody will care if first page is 21 messages, counting in the original topic.