diff --git a/selectVersion.js b/selectVersion.js
index 6b6d3ed..4513c27 100644
--- a/selectVersion.js
+++ b/selectVersion.js
@@ -1,90 +1,97 @@
 /**
 * selectVersion.js: select an angular distribution version.
 *
 * author: Christian Steiner
 * email: christian.steiner@unibas.ch
 * license: GPL v3
 *
 *    Copyright (C) University of Basel 2021  
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <https://www.gnu.org/licenses/> 
 **/
 
 /**
  * Script adds a selection that allows the user to select a specific angular distribution folder.
  * Based on the selection (or the current URL), the script loads the relevant scripts from the selected angular folder.
  * Reads a json-file 'versions.json' that describes the distribution versions.
  * (The json-file can be created with the python script 'addVersion.py'.)
  **/
 $(document).ready(function(){
    var currentUrl = new URL(location.href);
    $("body").prepend("<div id=\"selectContainer\" class=\"mui-select\"><select id=\"selectVersion\"></select></div>");
    $.getJSON("/versions.json", function(versions){
-      var currentVersion = writeBase(currentUrl, versions[0].number);
+      if (versions.length == 1){
+         $("body").remove("#selectVersion");
+         $("selectContainer").append("<select id=\"selectVersion\" disabled=\"true\"></select>");
+      } 
+      var currentVersion = writeBase(currentUrl, versions[0].number, versions.map(version =>version.number));
       $("body").append("<app-root><\/app-root>");
       versions.forEach(version =>{
          writeOptions(version, currentVersion);    
          writeScripts(version.scripts);
       });
    }).fail(function(){
       console.log("Could not read 'versions.json'!");
    });
    // Poll for fullscreen toggle change
    var fullscreen = false;
    setInterval(function(){
        if(location.href.includes('fullscreen=true') && !fullscreen){
             fullscreen = true;         
             $("#selectContainer").hide();
        } else if (location.href.includes('fullscreen=false') && fullscreen){
             fullscreen = false;         
             $("#selectContainer").show();
        }
    },500);
    // Act on selection changes -> change location to new version.
    $("#selectVersion").change(function(){
       var version = $(this).find("option:selected").attr("value");
       currentUrl = new URL(location.href);
       location.href = "/" + version + "/" + currentUrl.pathname.split('/').slice(2).join('/') + "?" + currentUrl.searchParams.toString();
    });
 });
 /**
  * Write the current base to the document body and return its value.
  **/
-function writeBase(currentUrl, newestVersion){
-  var baseHref = (currentUrl.pathname.split('/')[1] != '') ? currentUrl.pathname.split('/')[1] : newestVersion;
+function writeBase(currentUrl, newestVersion, versionNumbers){
+  var baseHref = currentUrl.pathname.split('/')[1];
+  if (baseHref == '' || !versionNumbers.includes(baseHref)){
+      baseHref = newestVersion;
+  }
   $("head").append("<base href=\"/" + baseHref + "/\"/>");
   return baseHref;
 }
 /**
  * Write the options of the version selection to #selectVersion.
  **/
 function writeOptions(version, currentVersion){
    if(version.number == currentVersion){
       $("#selectVersion").append("<option selected=\"selected\" value=\"" + version.number +"\">" + version.name + " " + version.number + "</option>");
    } else {
       $("#selectVersion").append("<option value=\"" + version.number +"\">" + version.name + " " + version.number + "</option>");
    }
 }
 /**
  * Write the scripts that should be loaded to the document body.
  **/
 function writeScripts(scripts){
    scripts.forEach(script =>{
       if(script.isModule){
          $("body").append("<script src=\"" + script.src + "\" type=\"module\"><\/script>");
       } else {
          $("body").append("<script src=\"" + script.src + "\" nomodule defer><\/script>");
       }
    });
 }