I've installed PAF5 on Linux a few times.  Most (or all) of those attempts ran into Font problems.  I.e. PAF would start up with little boxes in place of letters on the screen.  I never found a font I could load to solve the problem. 

The solution I found was to tell PAF5 to use fonts that are available on the system.  But it can be really hard to figure out how to do that when all the text is being displayed as empty boxes.

Here are the instructions to set the font preference:

To change the font(s) used by PAF you use the 'Tools' menu (the 6th item in the main menu across the top (File Edit Add View Search Tools Window Help)

1. Then, in the Tools menu the last item is 'Preferences'.
2. Then in the Preferences pop-up window 'Fonts' is the 6th tab.
3. Once you select the 'Fonts' tab you have 4 fonts to choose.
1. The first one is labelled 'Main Screen',
2. The second one is labelled 'Dialogs'.
3. The third is labelled 'Notes Edit Screen'.
   
4. The fourth is labelled 'Notes on Reports'.
   

I hope this helps.