Error during installation (Magento)

If you see an error like this, when you try to install Smart Slider:

CONNECT ERROR: Can't write to file:...

It is because of the non-ASCII characters in the filenames, and the Smart Slider can't be installed because of the filesystem restrictions. The solution is to open this file in your ftp: 

/downloader/lib/Mage/Archive/Abstract.php

Find this function in the code:
protected function _writeFile($destination, $data)
{     
	if(false === file_put_contents($destination, $data)) { 	
	throw new Mage_Exception("Can't write to file: " . $destination);     
	}     
	return true; 
}
Add this code before the "if" statement:
$destination = preg_replace('/[^(\x20-\x7F)]*/','', $destination);
It will replace those characters, and you will be able to install the Smart Slider:
protected function _writeFile($destination, $data)
{     
	$destination = preg_replace('/[^(\x20-\x7F)]*/','', $destination);
	if(false === file_put_contents($destination, $data)) { 	
	throw new Mage_Exception("Can't write to file: " . $destination);     
	}     
	return true; 
}