Problem: ‘Application blocked by Java Security’ error dialog box prompt when attempt to connect VPN.
Content Summary
Solution 1: Add websites to exception list in Java
Solution 2: Clear Java cache
Solution 3: Flush DNS
Solution 4: Clear web browser cache
Solution 5: Reinstall VPN Software
Solution 6: Install Windows updates
Solution 7: Reinstall Java
Reference
Solution 1: Add websites to exception list in Java
Step 1: Go to Start > type Java control panel and press Enter key.
Step 2: Go to Security tab. If Security Level is set to Very High then reduce it to High.
Step 3: Click on Edit Site List button.
Step 4: Click Add to type in the site URL.
Step 5: In the highlighted line, type the URL and then click OK button.
Step 6: After launching web browser and attempting the URL, Do you trust prompt will come up, tick Always trust boxes and then click OK.
Solution 2: Clear Java cache
Step 1: Go to Start > type Java control panel and press Enter key.
Step 2: Navigate to General tab, and click Settings under the temporary internet files section.
Step 3: Click Delete Files on the temporary files settings dialog box
Step 4: Click OK on the Delete Files and Applications prompt and follow the prompts.
Solution 3: Flush DNS
Step 1: Go to Start > Type cmd.
Step 2: Type ipconfig /flushdns
and press Enter.
Solution 4: Clear web browser cache
Step 1: Launch web browser e.g. Microsoft Edge
Step 2: Press Ctrl + Shift + Delete to access Clear recent history dialog.
Step 3: Under Time range to clear drop-down menu, select Everything.
Step 4: Make sure to check Cache box. Click on Clear Now.
Note: Ctrl + Shift + Delete can also be used to clear cache on other web browsers.
Solution 5: Reinstall VPN Software
Solution 6: Install Windows updates
Step 1: Go to Start > type windows update in the search box and then click on Windows Update to proceed.
Step 2: Check for updates and install the available updates.
Step 3: Restart PC after the update is completed.
Solution 7: Reinstall Java
Reference
What should I do when I see a security prompt from Java?
Why are Java applications blocked by your security settings with the latest Java?