There are a few reasons why the download may have been disrupted:
1. Antivirus, firewall, or security software may have disrupted the download.
If the download gets stuck at 0%, or if you experience a connection error message, you should start by temporarily disabling any firewalls on your local system. Many antivirus or internet security software packages include a firewall. You should also try disabling any firewalls that are built into your operating system, such as Windows Firewall.
The most common cause of the download failing once it has started is due to an antivirus or security program interfering with the installer. It is recommended that you temporarily pause the protection from any antivirus or security software on the system before performing the installation process. Once you have disabled your antivirus, close the installer and try launching it again. If you are prompted about overwriting existing files, select 'Yes' to overwrite them. It is preferred to have the installer overwrite any left-over files from the failed download so there are not any corrupted or half-completed files remaining on the system.
If you are using Windows, and you continue to experience problems with the installer even after disabling your antivirus, you should try restarting your system into 'Windows Safe Mode with Networking'. This will start Windows without starting any other programs on the system automatically. This will prevent any programs that may have been interfering with the installer from running in the background.
2. You may have lost your connection to the internet.
It is possible that your system lost it's internet connection during the download. Usually, the installer can resume after the connection is lost and then resumed, but if it was lost for an extended period of time, or if the network disruption caused some of the downloaded files to be corrupted, you may need to restart the installer. If you are using a laptop, it is recommended that you use a wired ethernet connection (if available) if you have experienced problems with the download.
If you are using a VPN or are connecting via a proxy server, you should try connecting directly to the internet instead of using these options.
3. Your system may have gone into 'Sleep' mode during the download process.
Check the power settings on your system. If you walked away from your system during the installation, and your computer went into 'sleep' mode, this will disrupt the process and you will not be able to continue with the installation without completely stopping it and then starting the installer again. The installer is designed to prevent the system from going into 'sleep' mode, but some systems may still go into 'sleep' mode if you are not interacting with the system for a long period of time while the installer is running.
4. You receive an Unexpected or Unknown error installing a toolbox into an existing installation.
If the pathdef.m was manually modified or edited this error may occur during the download portion of the installation regardless of using the downloaded installation files or installer. Run the following commands in MATLAB then try the installation again: