When I try to deauthorize it gives me the error: "Unable to Erase Authorization. Please try after some time."

If due to some reason, you are unable to deauthorize ADE, follow the below steps:

Mac: Navigate to /Users//Library/Application Support/Adobe/Digital Editions and drag the activation.dat file to the trash.

ADE will be deauthorized now.

Now Authorize ADE again.

Windows:

Choose Start > Run.

In the Open text box, type regedit and then press Enter. The Registry Editor opens.

In the left pane of the Registry Editor, locate the following registry key:

HKEY_CURRENT_USER\Software\Adobe\Adept

Right-click the Adept key and choose Delete.

In the Confirm Key Delete dialog, click OK.

Your authorization will be deleted.

ADE will be deauthorized now.

Now Authorize ADE again.