Thanks for the help again, you are by far the most active member of the community I have seen yet, and your help is very welcome. I found the block you was talking about and it all works perfectly, thank you.

This is great! Thanks.... the one small problem I am having with this is the order they appear on the page is not the order they appear in the template.

I have
[Page Attribute Display (Thumbnail)]
[composer control block]

but the thumbnail appears at the bottom of the page, under the composer control block. Is this a bug or do I have to specify the order they appear somewhere?

I have deleted all the blocks and re-added them, just in case the blocks were appearing chronologically (which would make no sense, but I was outta idea)

@ntisithoj

Just to clarify, are you saying that the position of the blocks changes?

If so, when do they change?

Can you take a before and after screenshot of this happening.

yes, exactly. Here are the screenshots

@ntisithoj

I am not quite sure what to look for in the livemode screenshot.

In editmode the thumbnail is above the blog. In the livemode the thumbnail appears below the blog.

@ntisithoj

Does this only happen for a certain page type or template?

I only tested on page template Right Sidebar] as this problem is appearing in the blog which uses that template.

I have three page types "Page", "Problog Post" and "Excerpt" (which was originally a copy of Problog Post) and it is the same on all three

@ntisithoj

Have you tested this with another theme?

Thank you, this helped a lot!

I'm having problems showing the thumbnail image on the applicable blog page (to allow users to edit the thumbnail image). I have created a custom attribute called 'thumbnail' which allows me to fetch the image on the blog page listing (this works fine). I have a Page Type called 'blog_entry' to which I have assigned the 'thumbnail' custom attribute under a composer form set called 'Content'. In this same set is 'Content' and 'Header Image', both of which are blocks, not attributes.

I can add the 'Content' and 'Header Image' elements to the Page Type Template (output) using the Composer Control block, but 'thumbnail' does not come up as a 'control' option in the composer control block form.

Can anyone tell me what I am doing wrong please? I had all this covered with 5.6 but trying to design similar composer template pages in 5.7 is driving me up the wall!

I'll answer my own question now, after more reading. To add a custom attribute to a page-type template, one needs to use the Page Attribute Display block, which can be found in the Multimedia section of the blocks side-panel. Also, the thumbnail can be changed by the user in the Composer interface, or edited as a thumbnail if you have locked the thumbnail image to a custom file thumbnail type. Such a lot has changed in 5.7!