Same here.. tried everything but can't find any text frame with overflow. There are no red dots showing when zooming out (and yes my "Show Text Flow" option is on). There were some text frames that didn't had any text, but after I checked the document 4 times I'm pretty done with this..
When trying to print an error is following. When clicking on "Ignore and continue" the print box appears. After I choosed the printer and clicked on "print", Affinity Publisher crashes and need to restart. My colleague has exactly the same problem. (Mac)
The only way to get it printed is to create an PDF first.