Universal Viewer, vertical scroll of pdf files

hi, I’m using Universal Viewer in my Omeka Classic exposition. It works fine but there is a single but not minor problem: in the case of pdf files, Universal Viewer cannot allow to make vertical scroll of the file, one thing that is possible to do with images files (jpg or png). Is it possible to solve this problem in any way?

Thank you in advance
Camilo Freire - Uruguay