Can't add PDFs as images anymore

[LoC]

So I have this large Scribus project with 220 pages. It includes about 20 PDF files that are embedded using image frames.

I finished this project about two weeks ago and sent a PDF to the print shop. Unfortunately, there were some issues with the resulting books, as the print shop did a really bad job with them, and now whe want wo print new ones.
Now we did not want to use the same exported pdf file, but fixy some minor issues first and export it again. Unfortunately, all the embedded PDF files are gone. Event though I did not change their location or naming, scribus now thinks that they were moved or they are somehow corrupted. I definitely did not touch them, and I can open them in any other PDF viewer.

Even deleting the image frame, recreating it and adding the PDFs again does not help; scribus refuses to display them..

I was not able to find anything on the internet about this issue, so I really hope to get some help here, as the project kind of needs to be finished..

Any help is greatly appreciated. Also, please excuse my bad english, I am not a native speaker..

I am using Scribus 1.5.8 on NixOS 23.05.

[MrB]

I'm suspecting some package update from your OS has modified or removed a Scribus dependency. What version of podofo do you have installed?

[LoC]

Scribus was build with version 0.9.8 of podofo on my system