If F-Secure is blocking or interfering with JDownloader, adding the JDownloader installation folder to F-Secure's exclusion list may resolve the issue.
Open F-Secure.
Go to Device Protection → Settings.
Open Manual Scan and click Show blocked applications and files.
Switch to the Excluded tab.
Click Add new.
Add your JDownloader installation folder. Optionally, you can also add your Java installation folder if Java-related files are being blocked.
Save the changes.
After adding these exclusions, F-Secure should no longer scan or block files inside these folders, allowing JDownloader to run and update normally.
Tags: Hosterproblem, javax.net.ssl.SSLHandshakeException((access_denied) Received fatal alert: access_denied)