Where debating everything under the sun is only the beginning

The problem I'm having right now is when I try to Import my opera bookmarks (either in .adr or .html format) I get the following error message: "Failed to open file for reading".

Will there be an opera extensions support in the future (such as ExtendTube, etc.)?

are there any interesting Opera specific extensions that cannot be ported to other APIs?

// Put userscript start tag here for GM compatibility. In Opera it's much faster to run it as an Opera UserJS.
// @name WWW Redirect
// @author Frans de Jonge (Frenzie)
// @version 1.02
// @description Automatically redirects to the www sub-domain on sites that return a 404 (not found) rather than a 301 (redirect) when trying to access the main domain.
// @include *
// ==/UserScript==

/*
This work is published under a Creative Commons Attribution-Noncommercial 2.0 license.
Copyright © Frans de Jonge 2009

CHANGELOG
1.0 2009-11-24 first release
1.01 2009-11-25 redirect didn't actually work, whoopsie; couple of "stupid sites" added
1.02 2010-02-02 added argenta.be
*/

(function () {
	// check if the stupid_sites variable already exists so that no problems arise if a potential separate settings file is used.
	if (!stupid_sites) {
		var stupid_sites = new Array();
	}
	
	// Stupid sites go here.
	// Simply add "stupid_sites[stupid_sites.length] = 'example.com';" at the bottom of this list to add your own stupid sites.
	stupid_sites[stupid_sites.length] = 'argenta.be';
	stupid_sites[stupid_sites.length] = 'eurolines.co.uk';
	stupid_sites[stupid_sites.length] = 'speedtest.nl';
//	stupid_sites[stupid_sites.length] = 'uitzendinggemist.nl';
	
	for ( var i in stupid_sites ) {
		if ( location.hostname == stupid_sites[i] ) 
			window.location='http://www.' + stupid_sites[i];
	}
})();

@SurpriZe, that is an odd message,  are you able to open these files with plain text editors (like Notepad or Wordpad)?

@Frenzie, UserJS is a bit separate topic, so far I've not decided yet how it should work in our case.

And is it really needed anyway (maybe except magic functions)?

e.element.text = e.element.text.replace(
  'areas.click(function(){ NrcOnePageView.Articles.showArticle(this);return false; });',
  ''
);

article_divs.forEach(function(div) {
  div.innerHTML = '<a href="'+getArticleHref(div)+'" style="display:block;width:100%;height:100%"></a>';
  //killEventListeners(div);
  jQuery(div).off('click');
});

when I try to Import my opera bookmarks (either in .adr or .html format) I get the following error message: "Failed to open file for reading".