Opencart error: Notice: Trying to access array offset on value of type null in ..../vendor/scss.inc.php on line 1753

If you see an error in opencart like below:

Notice: Trying to access array offset on the value of type null in .../vendor/scss.inc.php on line 1753

then the solution is: Open the file .../vendor/scss.inc.php and go to line as given in the above case it is 1753 where you will see code like below:

foreach ($args as $arg) {

    list($key, $value) = $arg;

    $key = $key[1];

    if (empty($key)) {

        $posArgs[] = $value;

    } else {

        $keyArgs[$key] = $value;

    }

}

Then change the line to the following, the changes done is in bold. 

foreach ($args as $arg) {

    list($key, $value) = $arg;

    if (!empty($key[1])) {

        $key = $key[1];

    }

    if (empty($key)) {

        $posArgs[] = $value;

    } else {

        $keyArgs[$key] = $value;

    }

}