If the VPN connection on iOS breaks down or cannot be established at all, you should first delete the associated VPN profile. You can find the appropriate option in the settings under “VPN”. There you select your service and click on “Delete VPN”. You then configure the connection data to your VPN server manually, or you can start the app for your VPN service – the profile will then be reinstalled. Also use the update function in the App Store to make sure that the relevant app is up to date. Uninstalling and reinstalling the VPN app may also help. If none of this helps, completely reset the network settings on your iPhone or iPad. Read this guide to find out how to do this.

You can find the VPN settings on your Mac under “System Preferences” -> “Network”. Here you should select your VPN server and, if you configured manually, check whether your access data is still up to date. If there are no errors here, you can delete the server from the network settings by clicking on the minus symbol in the bottom left corner of the window. You can then either reconfigure manually or start your VPN software so that it initiates an automatic reconfiguration. If this doesn’t help either, you could try using a different VPN protocol. If you configure manually, you can do this directly via the server settings; if you use software, you can do this in the program’s settings. A complete uninstallation and reinstallation of your VPN software can also help. A final option is to reset the PRAM on your Mac.

Only a few VPN services block dial-in from an administrative level when you are abroad. Most VPN providers allow you to connect from abroad. If you still can’t connect to the VPN server from there, you can usually solve the problem as follows: Go to the connection settings of your device/VPN and look for the function “Allow VPN when roaming”. Activate this function and the connection from abroad should work.

Some hotels and operators of other public networks block VPN services – this is annoying because VPNs provide additional security, especially in these environments. Connections are blocked based on the network ports that VPN applications use to establish a connection to the server. These ports vary depending on the VPN protocol used. It can therefore be useful to establish the connection using different protocols. You select these in your VPN software – with a bit of luck you will find a protocol whose ports are not blocked by the network operator. Some VPN services also have special protocols that do not use unusual ports and are therefore not recognized as VPNs by the network operator. VyprVPN is one such example; using the service could help in this case.

An active firewall could block certain network connections to protect you from harmful content. At the same time, such a blockage could prevent the establishment of a VPN connection. As a test, you should therefore deactivate all firewalls and check whether you can then establish a VPN connection. If this is the case, you should then configure your firewall so that these corresponding VPN ports are not blocked.

On the one hand, security programs such as a firewall can affect your connection to a VPN server. It helps if you set appropriate exceptions for the VPN connection in the program settings. Slow connections also occur if you connect to a server that is particularly far away. Alternatively, try switching to a server location near you. However, slow speeds can also be due to the VPN service you have chosen. With some providers, the connection is significantly slower than with others. The only thing that helps here is switching to a faster VPN service.

If you have manually configured a VPN server under Windows, you should check that the data provided is up to date in the settings under “Network and Internet” -> “VPN”. Also make sure that the options “Allow VPN over metered networks” and “Allow VPN when roaming” are activated here. If you use a VPN service with its own software, you should completely uninstall it and reinstall it. If the problem persists, you could try using a different VPN protocol. If you configure manually, you can do this directly via the server settings; if you use software, you can do this in the settings of that software. If this is not a solution either, then probably as a last resort, reset your network settings.

First, make sure you are using the latest version of the VPN program. If not, all necessary updates will be installed. If you are still having problems, uninstalling and reinstalling the software may help. Some VPN services also have a function to reset the program to the default settings. In some cases, this can also help. Disabling special additional functions (such as the kill switch) or changing the VPN protocol used can also help.

VPN connections are handled via different network ports than regular Internet connections. For security reasons, unusual ports may be blocked by your router: If this affects the ports of your VPN software, you will not be able to establish a connection to the server. Which ports you need to open to establish the connection varies depending on the VPN protocol and service you are using – you can get the relevant information either on your VPN provider’s website or from your network administrator. You can then start to open the required ports for use in your router’s settings.

You cannot delete individual VPN profiles from the system on Android, so if you have problems you should completely uninstall your VPN app and then reinstall it. Make sure you are using the latest version of the app in the Google Play Store. If the problem cannot be solved, you can reset the network settings – follow these instructions.