Thanks for reporting this issue.
Think it is caused by this line in icms_version.php:

$modversion['modname'] = 'impression';

This is true. If I delete this line (same like version 1.11), works as well.

Looks like the issue is not caused by the line mentioned earlier but by the name of the module in the naming of a class.
For example, mod_impression_ArticlesHandler should be renamed to mod_<dirname>_ArticlesHandler

One way to avoid this issue is to utilise the stand-alone "clone.php" code from Smartsection.

This routine will allow you to rename all the constants, names, functions etc which are unique to a module - example SmartSection, SMARTSECTION, smartsection to an alternative one.

So in this case: Impression, IMPRESSION, impression (and other combinations) could be renamed by the routine to: Article, ARTICLE, article (etc)

The code does work to clone other IPF modules - as I have used this with News_IPF .. however it really could do with updating to make easier to use.

Just did a quick test with clone.php and it seems to work fine.

<?php

/*

Usage:
	
	Copy clone.php in <xoops_root>
	Change current working directory to <xoops_root>
	Update mappings as per new modulename.

	php -q clone.php 

*/

// ##########################################################
//	Define your mapping here
// ##########################################################
$patterns = array(
  // first one must be module directory name
  'impression'  => 'impressionclone', 
  'IMPRESSION'  => 'IMPRESSIONCLONE' 
);

$patKeys = array_keys($patterns);
$patValues = array_values($patterns);

// work around for PHP < 5.0.x
if(!function_exists('file_put_contents')) {
  function file_put_contents($filename, $data, $file_append = false) {
    $fp = fopen($filename, (!$file_append ? 'w+' : 'a+'));
    if(!$fp) {
      trigger_error('file_put_contents cannot write in file.', E_USER_ERROR);
      return;
    }
    fputs($fp, $data);
    fclose($fp);
  }
}

// recursive clonning script
function cloneFileFolder($path) 
{
  global $patKeys;
  global $patValues;
  
  $newPath = str_replace($patKeys[0], $patValues[0], $path);

  if (is_dir($path)) 
  {
    // create new dir
    mkdir($newPath);
    
    // check all files in dir, and process it
    if ($handle = opendir($path))
    {
      while ($file = readdir($handle)) 
      {
        if ($file != '.' && $file != '..') 
        {
          cloneFileFolder("$path/$file");
        }
      }
      closedir($handle);  
    }
  } 
  else 
  {
    if(preg_match('/(.jpg|.gif|.png|.zip)$/i', $path)) 
    {
      copy($path, $newPath);
    } 
    else 
    {
      // file, read it
      $content = file_get_contents($path);
      $content = str_replace($patKeys, $patValues, $content);
      file_put_contents($newPath, $content);
    }
  }
}

cloneFileFolder('modules/impression');

echo "Happy cloning...\n";
echo "check directory modules/" . $patterns['impression'] . " for cloned module \n";
echo "Consider modifying new module by editing language/english/modinfo.php and images/mysection_slogo.png manually (if you care)\n";

?>