Bitdefender VPN is unable to function with a 4G mobile connection

Alexandre Lintz
edited April 19 in VPN

VPN functions properly on local Wi-Fi, but encounters error 9 or error 304 when using a 4G mobile connection. Can anyone provide any suggestions to resolve this issue?

Best Answer


  • Dear Flexx,

    Thank you for your swift response. I appreciate the troubleshooting steps you provided; however, I have attempted each of them without any positive results.

    I noticed that the log tools you shared are specifically designed for Windows-based troubleshooting. As my issue pertains to the Bitdefender VPN app for iOS on my iPhone, I'm unable to generate error logs using those methods.

    Could you please suggest alternative solutions or steps that are applicable to my situation? I look forward to resolving this issue promptly.

    Best regards,


  • Hello @Alexandre Lintz,

    I'll try to help you out as well.

    Usually, if you’re having trouble with Bitdefender VPN, just turning your device off and then back on again can fix the problem. This works when the operating system or other services don’t start up properly.

    If you restart the iPhone or iPad and are still experiencing VPN errors, continue with the steps below.

    Step one: Reinstall Bitdefender VPN

    To make sure the VPN app is intact, and you have the latest version it is recommended to reinstall Bitdefender. Follow these steps:

    1. Uninstall Bitdefender VPN from your iOS device. If you need help uninstalling the app, please read this article.
    2. Then, reinstall Bitdefender VPN from App Store.

    Step two: Grant permissions

    If Bitdefender VPN doesn’t connect or shows errors on iOS, make sure the necessary permissions were granted to the Bitdefender VPN app:

    1. Go to 
    2. Settings →  General → scroll down and select VPN → tap the ⓘ icon next to Bitdefender VPN → choose Delete VPN → tap Delete to confirm.
    3. Next, open the Bitdefender VPN app and try to connect.
    4. Choose Allow in the ‘BitdefenderVPN would like to add VPN Configurations’ screen.
    5. Enter your iPhone / iPad passcode, to allow the VPN connection.

    Step three: Change your DNS

    If you are currently using the default DNS (Domain Name System) from your Internet provider, switch to a third-party DNS server that might be faster and reliable.

    To learn how to change your DNS settings on iOS follow this link.

    Step four: Try a different network

    If the VPN errors persist after going through the previous steps, something on your local network is most likely still blocking the connection to the Bitdefender servers.

    Check if you can use Bitdefender VPN after connecting your iOS device to another network (Wi-Fi, hotspot, cellular data).

    Let us know how it goes and if the above steps were helpful.

    If the error persists, kindly contact our Support Teams as more information might be required to troubleshoot this. You can get in touch with our engineers by choosing one of the contact channels available here:



  • Dear Alex,

    I appreciate your swift response. Unfortunately, after following the steps you provided, I am still experiencing issues with the Bitdefender VPN on my iPhone. While it functions smoothly on my local Wi-Fi connection, it ceases to work once I switch to a 4G mobile network.

    Could you kindly offer any alternative solutions to address this problem? Your assistance would be greatly appreciated.

    Best regards,


  • Well @Alexandre Lintz, I'm afraid I have no other ace up my sleeve. So, the best I can do is to recommend you to get in touch with our engineers for further troubleshooting, as I have exhausted all the alternative solutions I was thinking of.

    Click on the link below to reach our engineers and choose one of the available contact channels (chat, phone, email/ticket):

    I'm sorry I couldn't do more to help.

    Let us know how it goes, I'm very curious to know what is the culprit here.