Instant Crash when Pages Reordered or Blank Page Deleted

[Clanks]

I am having repeated crashes when reordering pages in a four page document.  There are some blank pages that I am trying to get rid of and then rearrange page order for different exports.  It has become impossible.

The first file is the .afpub that is crashing when a page is moved or a blank page deleted: Dec2019Jan2020Beaconlayout.afpub

The second file is the crash report: AffinityPublisherCrash.rtf

The third final is the final product that we are trying to achieve, which we created by exporting one page at a time and then building in Preview: Dec2019Jan2020BeaconWebResolution.pdf

This is very aggravating and time consuming.

Clanks McGraw--in Philly

[thomaso]

I was able to delete in your .afpub the spreads 2/3 and 6/7 successfully.
Here the .afpub reduced to 4 pages as shown in your PDF:  Dec2019Jan2020Beaconlayout_4 pages.afpub

Whereas when trying to delete page 2 as a single page I got a crash, too. *
I also got a crash for this action in APu beta v518, which is a pity because in v502 the pages panel got some improvement but that obviously doesn't help in this case.

EDIT: Supplement: I think the culprit for the crash is on page 4 an orphaned layer, (auto-)named as "(Master Page)". There is neither a master in the pages panel nor does this layer occur on in the document window layout view. This seems to cause the crash of single page before 4 because it would force all layers of page 4 to become moved from a left to a right page whereas a deletion of spread 2/3 simply alters the internal numbering.
* After deleting this orphaned master layer I was able to delete pg 2 with no harm.

[Clanks]

Problem solved!  You are a life saver.  Thank you! Danke!

[thomaso]

Glad it works for you! – I still would like to understand how that happened: Did you initially start with a master page which you deleted later but not before page 4 was created? And did you move this layer in the layers hierarchy? Or were does this layer "(Master Page)" come from?

[Clanks]

I am not too sure.  I believe a master page was created that was later deleted, and the specific pages that it had been applied to were not updated.

[Jon P]

Nicely investigated @thomaso.

I am indeed keen to see if we can reproduce how this happened, I've had a poke around and not had much luck reproducing it so far, but it does indeed look like it wasn't cleared from a page when the master layer was deleted which should never be the case.

If you find this again or have any more info to help us reproduce this from scratch let me know!