No PDF thumbnails when contained in ZIP

[sergejzr]

What steps does it take to reproduce the issue?
Create/Edit a dataset
Upload a zip file containing pdf files

• When does this issue occur?
  always when uploading a zip file containing pdfs

• Which page(s) does it occurs on?
  Upload preview page editdatafiles.xhtml
  Data set view page: /dataset.xhtml

• What happens?
  The thumbnail of the pdf file remains "unknown" whilst thumbnails for png files are generated and displayed correctly

• To whom does it occur (all users, curators, superusers)?
  all users

• What did you expect to happen?

Which version of Dataverse are you using?

v. 5.4 build 413-ea91390

Any related open or closed issues to this bug report?
A general discussion on thumbnail improvements can be related: #6450

[pdurbin]

@sergejzr sorry for the slow reply. I'm a little surprised this doesn't work. When you get a minute, can you please try it at https://demo.dataverse.org ?

[sergejzr]

Turned out it was a general thumbnail creation problem. Solved in the meanwhile. Thank you!