Alirat

My problem is solved with a restart of my Mac. Have had a few hiccups after updating to Catalina.

Here's a silly suggestion. Convert the clients to using Affinity. It's not a huge capital outlay and there is no subscription...

Hi there to you guys,
 
I've spent a couple of days looking into various options concerning showing bleed marks in the exported/slices option in export persona.  I've been designing my book covers in AD using 3 Art Boards in the same document.  Obviously there is an artboard for the "Front Cover" then another for the "Spine" and lastly one for the "Back Cover".
Here is the procedure that I've followed to have the bleed visible in the exported pdf document of the book cover as one document.
Seeing I'm creating my book cover to a trim size of A5 which is 148mm x 210mm, I create the document at that exact size.  Once I have the 1st Artboard created in AD which is for the Front Cover, I hold down the Option key on Mac and drag out a copy of the First Artboard into a second one for the Back Cover and lay it along the left of the first Artboard. I then drag out another Artboard using the Option Key on Mac and resize it to the spine width needed.  The spine gets moved into position so that it is in between the front and back covers.  I then rename all 3 Artboards individually by the following :- "Front Cover", "Spine" and "Back Cover." I then go to the document setup in each artboard and set the bleed sizes to 3mm all round.  This I do for all the artboards.  I also set the Margin sizes to be 5mm all round as well. I then create the backgrounds for all Artboards to extend beyond the Artboard sizes by 3 mm all round.  Therefore, only the Backgrounds, when clicked on show that they extend over the edge of the Artboards by 3mm.  If you collapse the layer structure groups to just show the artboard, you won't see the background extending over the sides.  This is important to understand. I then create all the inner content on the Front, Back and Spine Artboards to stay within the margins I set in the document setup under the file menu. Once my book cover is complete, I group all three Artboards in the Draw Persona into one group and rename it to something like "Book Cover". I then go into the Export Persona and click on the "Layers" Tab.  Under the layers Tab I see the "Book Cover" Group there. I then go to the slice tool and drag out one slice over the whole document.  The size of the slice needs to be exactly the same size as the full book cover measurement in mm plus the 3 mm  added on.  Therefore the slice is larger than the actual document.  This will accommodate the bleed of 3 mm set around the whole document. I then click on the slices Tab, still in the Export Persona, and rename the slice I just created to another name. In the Slices Tab there is another slice called  background.  I only select the renamed slice that I created.  I do not select the background slice. I then click on Export Options Tab and choose the PDF Print option. I then scroll down to the section of "Include Bleed"and select it, and then select "Include crop marks. I then deselect "Include registration marks", "Include colour bars", "Include page information". "Subset Fonts" and "Allow advanced features" are both selected. I then click on the Slices Tab again. I make sure that the slice I created is still selected and has a check in the check box. I then click on the "Export Slices" button at the bottom of the page. The entire "Book Cover Image" is exported as a PDF document to a location I can choose on my Mac.  You'll notice when you view the exported book cover, that it is complete with the 3mm bleed all the way round and the crop marks are at those positions on all 4 corners of the document with a white border around.  The white border is ok.  That's it. 
This method has worked for me after much trial and error. Attached is an incomplete book cover to illustrate this process. Book Cover.pdf

Here's a silly suggestion. Convert the clients to using Affinity. It's not a huge capital outlay and there is no subscription...

Hi there  - I have just received the Photo Workbook in the post and am working my through. I am a very experienced Photoshop user but wanted to make sure my workflow took advantage of all Affinity Photo has to offer.  I am loving it. The files are downloadable so you can work at your own pace, and the teaching is arranged in such a way that nothing gets missed. I have discovered a couple of extraordinary features that I didn't know existed (the selection refinement on hair for example - mind blown!) and the HDR and stacking which does act differently from PS. I need to get up to speed quickly as I have dumped Adobe and far from being a waste of time, these exercises are really helping. I tend to learn by doing, and watching a video is all very well and good but it does go in one brain cell and out the other. So I'm a YES to the books.

Good morning. Hello;
And welcome to both of you Alirat. and nikolai. ylirotu
Affinity is a very promising product.
Yours sincerely.