There is a single version of the client for Adaxes 2017 and you can download it here.
However, it looks like the issue is not related to the Self-Service Client version. Most probably, the Access Denied error message (after which users can still reset their passwords) is displayed because Auto-Logon is enabled for the Web Interface used by the client. To remedy the issue, you need to disable the feature:
i. Check the Web Interface used by the client
- Launch Adaxes Administration Console.
- In the Console Tree, expand your service node.
- Navigate to Configuration\Password Self-Service and select Windows Integration.
- The URL of the Web Interface used by the client will be displayed in the Web Interface URL field on the right.
ii. Disable Auto-Logon
- Launch Adaxes Web Interface Customization tool.
- Select the Web Interface you need and activate the Sign In tab.
- Click Disable Automatic Logon.
- Click OK twice.
- For the changes to apply, restart the computers where the Password Self-Service client is installed multiple times.