In 10.15 macOS update fonts used by the program were misplaced in the system. If after converting the document into searchable PDF in FineReader Pro for Mac you are not able to highlight or select text in Apple Preview program, please use one of the solutions below:

Using Font Book

1. Open Font Book from Launchpad or find it using search;

2. Go to Font Book > Preferences and in Default install location choose Computer;

3. On the toolbar press File > Add fonts;

4. Choose folder Macintosh HD/System/Library/Fonts/Supplemental;

5. Hold Command key, choose Arial.ttf, Courier New.ttf and Times New Roman.ttf;

6.  Press Open and enter the password.

Copying fonts to the correct folder

First approach:

1. Ctrl-Click Finder  and choose Go to Folder...(or hit Command+Shift+G);
2. Go to the directory /System/Library/Fonts/Supplemental;
   Important! The path should be typed in exactly as shown above.
   
3. Hold Command key, choose Arial.ttf, Courier New.ttf and Times New Roman.ttf and copy them (Command+C);
4. Go to the directory /Library/Fonts;
5. Past these fonts to this directory;
6. Restart your Mac.

Second approach:

1. Go to Launchpad > Disk Utility;
2. Ctrl-Click Macintosh HD and choose Show in Finder;
3. Go to System > Library > Fonts > Supplemental;
4. Hold Command key, choose Arial.ttf, Courier New.ttf and Times New Roman.ttf and copy them (Command+C);
5. Collapse System folder and open Macintosh HD > Library > Fonts;
6. Past these fonts to this directory;
7. Restart your Mac.

After that you should be able to select text in Preview in newly recognized PDF files.