This seems to be common issue, and there exist a lot of posts about this issue but none of them works for me.
I have a custom post type (portfolio) with a page pagination.
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1; echo '<a href="'.get_pagenum_link($paged+1).'">Next Page</a>';
When Set the permalinks settings to 'Default' it works fine.
When Set the permalinks to any custom structure it leads to the 404 page.
This is driving me crazy. Can't find any solution. I don't have a page or post which have the slugname 'page', so this can't be the problem. I refreshed the permlinks multiple times, which doesn't work either.
NB: default Blog page works fine for both permalinks settings
I would really appreciate some hlep on this. Thanks