The Picker does not send information to the Citavi project

The Picker appears in Firefox (or Chrome), but when you click the ISBN icon or select Add webpage as reference, no information is added to the open Citavi project.

Causes

Click the box to see the solution

You're using an older version of the Picker with the 64-bit version of Firefox

The Picker for Firefox was installed with a version that did not yet support the 64-bit version of Firefox (Citavi 5.2 and earlier).

You can tell which version you are using by checking the installation location: the 64-bit version can be found in the folder C:\Program Files, while the 32-bit version can be found in the folder C:\Program Files (x86).

Older Picker versions cannot be used with Firefox 64-bit. To fix the problem follow the steps below:

Uninstall the Citavi Picker. On the Windows Control Panel, click Programs and features > Citavi [Version] > Change > Next > Modify > Next. Click the hard drive symbol next to Picker for Firefox and then select This feature, and all subfeatures, will not be available. Click Next and continue through the Setup.
Install the Picker for Firefox from the Firefox store: https://addons.mozilla.org/en-US/firefox/addon/citavi-picker/

An antivirus program is blocking the Picker

Your antivirus program is blocking the communication between the Picker in your browser and your Citavi installation.

Solution

Add the service C:\Program Files (x86)\Citavi 6\Pickers\Chrome\ChromePickerBroker.exe to your antivirus program's whitelist.

Instructions for individual programs: Avast, Avira, Kaspersky, Malwarebytes