PDF Files Not Showing Up in CorelDraw`

All of the sudden Corel and Adobe Acrobat seem to not be communicating well.  It started yesterday when I saved Corel files to pdf. When I would look at it in Adobe Acrobat, some pages were blank.  Shut both programs and reopened, seemed to resolve issue.  Now when I try to open certain files, File Explorer doesn't even show all of the pdf files, but it does some of them.  Tried to fix Acrobat, Uninstalled and Re-installed, and issues persist.  I am trying to open a pdf document in Corel but when I go to my files while in Corel the pdf files do not show up.  But they are there if I am in Adobe Acrobat.  Please help!