PDF Indexer

Hello i buy this component on June 06 2019.

Now we have update to PHP 8.0 and the component don't work any more. We receive blank screen with 500 error.
How we can resolve it ? 

Fatal error: Declaration of DocIndexerController::display() must be compatible with Joomla\CMS\MVC\Controller\BaseController::display($cachable = false, $urlparams = []) in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/controller.php on line 36

this is the error.

Now we have fix fatal error

in this way: 

function display( $cachable = false, $urlparams = false )

but we receive a lot of warning:

Warning: Undefined variable $lists in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/views/configuration/view.html.php on line 30
Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/models/docs.php on line 51

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/components/com_docindexer/helper/helper.php on line 44

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/views/docs/view.html.php on line 27

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/models/docs.php on line 152

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/models/docs.php on line 154

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/models/docs.php on line 138

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/views/docs/view.html.php on line 35

Notice: Only variables should be assigned by reference in /Applications/MAMP/htdocs/OAM/administrator/components/com_docindexer/views/docs/view.html.php on line 36

and many other

Hi Sandro,
Your PDF Indexer version isn't compatible with PHP8. You need to purchase latest version of extension and install it to get the problem resolved
Thanks
Dam