E_AUTH_BAD_DEVICE_KEY_OR_PKCS12 error

Using a Mac with High Sierra. Using ADE 4.5.8.182914. When I try to load an ebook, I get the error message "E_AUTH_BAD_DEVICE_KEY_OR_PKCS12", which is a deauthorization error message. I have researched and know that I have to go to Users/[[Your user account]]/Library/Application Support/Adobe/Digital Editions and drag the activation.dat file to the trash. The problem is that there is no Digital Editions in Users/[[Your user account]]/Library/Application Support/Adobe/Digital Editions and drag the activation.dat file to the trash. I've also done a search on my computer for an activation.dat file, but there is none. I've tried uninstalling and reinstalling ADE. I've tried uninstalling and installing an older version (3.0) with the same results. Any suggestions?

Thanks,

Craig