I was able to solve the problem.
In my case, the problem was with the file permissions on the server. I changed the permissions on the uploads folder, subfolders and image files from the more the restrictive 775 for folders and 664 for files to 755 for folders and 644 for files. You can do this through FTP or the File Manager in your cpanel. Once I made those changes, the problem went away.
If you aren't able to change the permssions, it may be due to ownership settings. I had to have the hosting service fix the ownership before I could make the permissions changes as that was a bit out of my expertise.