mysqld: error while loading shared libraries: libprotobuf-lite.so.3.19.4: cannot open shared object file: No such file or directory

This error message indicates that the MySQL server is unable to find the required shared library "libprotobuf-lite.so.3.19.4" on the system. The library may be missing or not installed in the correct location.

To resolve this issue, try the following steps:

1. Check if the library is installed on the system by running the command:

`ldconfig -p | grep libprotobuf-lite.so.3.19.4`

If the library is not found, you may need to install it using your system's package manager or download it from the internet and install it manually.

2. If the library is installed but not in the correct location, you can create a symbolic link to the correct location using the command:

`sudo ln -s /path/to/libprotobuf-lite.so.3.19.4 /usr/lib/libprotobuf-lite.so.3.19.4`

Replace "/path/to" with the actual path to the library on your system.

3. Once the library is installed or linked correctly, restart the MySQL server and check if the error has been resolved.

`sudo systemctl restart mysql`

If the issue persists or you are unsure about how to proceed, it may be best to consult a system administrator or technical support for further assistance.