To upgrade Wialon Local from version 1904 to version 2004, follow the steps below.

1. Upgrade the operating system Debian to the version 10 (Buster).

2. Install the pigz and curl utilities. To do this, log in to the terminal on behalf of the main user (root) and run the following command:

   apt-get install pigz curl
   

3. Upgrade Node.js to the version 10.x, by running on behalf of the main user (root) the following commands:

   cd /home/wialon/wlocal/
   service wlocal stop
   ./adf_script stop
   apt-get install -y curl
   curl -sL https://deb.nodesource.com/setup_10.x | bash -
   apt-get install -y nodejs
   npm -g install forever
   npm install
   chown -R wialon:wialon /home/wialon/
   service wlocal restart
   

   Check the availability of your sites after they restart. To update Node.js, you can also contact technical support. In this case, in the letter specify SSH credentials (IP, login and password) to access the server console.
   The instruction is also located on the official site of the Node.js developer.

4. Install the version 2004 of Wialon Local .