Save function for pdf files not working

I just moved DTPO to a new iMac. I had several problems initially getting everything to work and thought all issues were resolved. But now I discover that I can’t save changes to pdf files (ie highlighting text) unless I open the pdf in Adobe Acrobat, highlight text there, and then close the file. The save function in the menu bar of DPTO is not working. Any suggestions for how to turn it on?

Please start a Support Ticket.