I have re-installed Pdf24 Creator 8.8.2 and pdf files are readed using AcrobatReaderDC. I think that this problem was due to Google Chrome I was using. Now I am using Firefox and that problem is solved (I can copy/paste the pdf text and it is readable) BUT I FIND ANOTHER PROBLEM !:
WHEN I PRINT A WEB PAGE WITH PDF24 ,IN THE RESULTING PDF ALL THE LINKS ARE LOST !! so one problem solved but another rised (for the law of compensation)