I wonder if 'Create new page as a copy' has a bug in Apex 4.2.0?
I used this function for a couple of pages when creating a new application (and I needed a couple of my 'standard' pages from another app).
In various locations (like under Report attributes on tabular form pages, and under buttons) the template was either missing, or just showing a long number (like a database internal ID).
After I upgraded to the latest apex 4.2.1 the page copy seems to be much better.
But I still have to manually check all my copied pages...
I made some queries to help to find the problems.
-- Buttons with mismatch on template
select * from APEX_040200.WWV_FLOW_STEP_BUTTONS b
left join APEX_040200.WWV_FLOW_BUTTON_TEMPLATES t on b.button_image = 'template:'||t.id
where b.button_image like 'template%'
and not exists (select 9 from APEX_040200.WWV_FLOW_BUTTON_TEMPLATES t1
where b.button_image = 'template:'||t1.id and t1.flow_id = b.flow_id);
-- Regions (in application 119) with mismatch on template
select * from APEX_040200.WWV_FLOW_PAGE_PLUGS p
left join APEX_040200.WWV_FLOW_PAGE_PLUG_TEMPLATES t on p.plug_template = t.id
p.flow_id = 119
and p.plug_template > 0
and not exists (select 9 from APEX_040200.WWV_FLOW_PAGE_PLUG_TEMPLATES t1 where p.plug_template = t1.id and p.flow_id = t1.flow_id);