Und noch ein kleines Script, was nicht mehr geht

// buttonCloseTab.uc.js - Button > Firefox Tabs schliessen
  
  (function() {
      
  if (!window.gBrowser) return;
    
    try {
        CustomizableUI.createWidget({
            id: 'fp-closetabs',
            type: 'custom',
            defaultArea: CustomizableUI.AREA_NAVBAR,
            onBuild: function(aDocument) {            
                var toolbaritem = aDocument.createElementNS('http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul', 'toolbarbutton');
                var props = {
                    id: 'fp-closetabs',
                    class: 'toolbarbutton-1 chromeclass-toolbar-additional',
                    label: 'Aktuellen Tab schließen',
                    tooltiptext: 'Aktuellen Tab schließen',
                    style: 'list-style-image: url(\'data:image/svg+xml;charset=utf-8,<svg xmlns="http://www.w3.org/2000/svg" color="dodgerblue" width="12" height="12" viewBox="0 0 16 16"><path fill="currentColor" fill-opacity="context-fill-opacity" d="M9.414 8l5.293-5.293a1 1 0 0 0-1.414-1.414L8 6.586 2.707 1.293a1 1 0 0 0-1.414 1.414L6.586 8l-5.293 5.293a1 1 0 1 0 1.414 1.414L8 9.414l5.293 5.293a1 1 0 0 0 1.414-1.414z"></path></svg>\')',
                   // onclick: 'if (event.button == 0) { \
                        //    BrowserCommands.closeTabOrWindow();\
                          //       }; '
                };
                for (var p in props)
                    toolbaritem.setAttribute(p, props[p]);
					toolbaritem.addEventListener('click', event => {
					if (event.button == 0) { 
                            BrowserCommands.closeTabOrWindow();
                                 }; 
					});
                return toolbaritem;
            }
        });
    } catch(e) { };
   
})();

// buttonCloseTab.uc.js - Button > Firefox Tabs schliessen

  (function() {

  if (!window.gBrowser) return;

    try {
        CustomizableUI.createWidget({
            id: 'fp-closetabs',
            type: 'custom',
            defaultArea: CustomizableUI.AREA_NAVBAR,
            onBuild: function(aDocument) {
                var toolbaritem = aDocument.createElementNS('http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul', 'toolbarbutton');
                var props = {
                    id: 'fp-closetabs',
                    class: 'toolbarbutton-1 chromeclass-toolbar-additional',
                    label: 'Aktuellen Tab schließen',
                    tooltiptext: 'Aktuellen Tab schließen',
                    style: 'list-style-image: url(\'data:image/svg+xml;charset=utf-8,<svg xmlns="http://www.w3.org/2000/svg" color="dodgerblue" width="12" height="12" viewBox="0 0 16 16"><path fill="currentColor" fill-opacity="context-fill-opacity" d="M9.414 8l5.293-5.293a1 1 0 0 0-1.414-1.414L8 6.586 2.707 1.293a1 1 0 0 0-1.414 1.414L6.586 8l-5.293 5.293a1 1 0 1 0 1.414 1.414L8 9.414l5.293 5.293a1 1 0 0 0 1.414-1.414z"></path></svg>\')',
                   // onclick: 'if (event.button == 0) { \
                        //    BrowserCommands.closeTabOrWindow();\
                          //       }; '
                };
                for (var p in props)
                    toolbaritem.setAttribute(p, props[p]);
					//toolbaritem.addEventListener('click', event => {
					//if (event.button == 0) {
                    //       BrowserCommands.closeTabOrWindow();
                    //      };
					//});
                return toolbaritem;
            }
        });
    } catch(e) { };

    // Fix #2
    document.getElementById('fp-closetabs').addEventListener('click', event => {
        if (event.button === 0) {
             BrowserCommands.closeTabOrWindow();
         }
     });

})();

// ==UserScript== 
// @name           
// @description    Tab schließen + Kontextmenü auch in dem Einstellungsfenster
// @charset        UTF-8
// @author         @aborix 5. November 2020
// @version        v2025.05.02
// @note           Vorlage Script von @aborix (+ Änderungen von @milupo aus dem Fuchsforum 1.10.24)
// @note           Anpassung von @milupo ( 08.10.2024 ab Fx 132 > tabbrowser-tabbox statt appcontent)
// Source          https://www.camp-firefox.de/forum/thema/131567/?postID=1158359#post1158359
// EventListener   https://www.camp-firefox.de/forum/thema/131567/?postID=1270981#post1270981


(function() {

  if (!window.gBrowser)
    return;

  var contextMenu = document.getElementById('contentAreaContextMenu');
  var menuseparator = document.createXULElement('menuseparator');
  menuseparator.id = 'context-sep-closetab';
  contextMenu.append(menuseparator);
  var menuitem = document.createXULElement('menuitem');
  menuitem.id = 'context-closetab';
  menuitem.setAttribute('label', 'Tab schließen');
  //menuitem.setAttribute('oncommand', 'gBrowser.removeCurrentTab();');
  //Fix1
  //menuitem.addEventListener('click', () => {
  //  BrowserCommands.closeTabOrWindow();
  //});
  contextMenu.append(menuitem);

  //var appcontent = document.getElementById('appcontent');
  var appcontent = document.getElementById('tabbrowser-tabbox');
  appcontent.addEventListener('contextmenu', event => { 
    setTimeout(() => {
      if (gContextMenu && !gContextMenu.shouldDisplay) {
        for (let string of 'back forward reload bookmarkpage'.split(' ')) {
          document.getElementById('context-' + string).removeAttribute('hidden');
        }
        document.getElementById('context-stop').setAttribute('hidden', 'true');
        const A = 'navigation sep-navigation savepage sep-paste selectall sep-viewsource viewsource viewinfo sep-bidi inspect-a11y inspect sep-closetab closetab'.split(' ');
        for (let node of contextMenu.childNodes) {
          if (A.includes(node.id.substring(8)))
            node.removeAttribute('hidden');
          else
            node.setAttribute('hidden', 'true');
        }
        contextMenu.openPopupAtScreen(event.screenX, event.screenY, true, event);
      }
    }, 50);
  });

      // Fix #2
      document.getElementById('context-closetab').addEventListener('click', event => {
             BrowserCommands.closeTabOrWindow();
     });
})();