diff --git a/Message/Request/Request.js b/Message/Request/Request.js
index 98c8997..a60d1fe 100644
--- a/Message/Request/Request.js
+++ b/Message/Request/Request.js
@@ -87,7 +87,10 @@
                 return jsOMS.Message.Request.BrowserType.EDGE;
             } else if (!!window.chrome && !!window.chrome.webstore) {
                 return jsOMS.Message.Request.BrowserType.CHROME;
-            } else if ((isChrome || isOpera) && !!window.CSS) {
+            } else if (((typeof isChrome !== 'undefined' && isChrome)
+                    || (typeof isOpera !== 'undefined' && isOpera))
+                && !!window.CSS
+            ) {
                 return jsOMS.Message.Request.BrowserType.BLINK;
             }
 
diff --git a/UI/Component/Tab.js b/UI/Component/Tab.js
index c7dc459..9c3cae2 100644
--- a/UI/Component/Tab.js
+++ b/UI/Component/Tab.js
@@ -41,7 +41,7 @@
                     this.bindElement(e);
                 }
             } else {
-                const tabs = document.querySelectorAll('.tabview'),
+                const tabs = document.querySelectorAll('.tab'),
                 length = !tabs ? 0 : tabs.length;
 
                 for (let i = 0; i < length; ++i) {
@@ -61,8 +61,6 @@
          */
         bindElement (e)
         {
-            this.activateTabUri(e);
-
             const nodes = e.querySelectorAll('.tab-links li'),
                 length = nodes.length;
 
@@ -73,18 +71,37 @@
 
                     /* Change Tab */
                     /* Remove selected tab */
-                    fragmentString = jsOMS.ltrim(fragmentString.replace(this.parentNode.getElementsByClassName('active')[0].getElementsByTagName('label')[0].getAttribute('for'), ''), ',');
-                    jsOMS.removeClass(this.parentNode.getElementsByClassName('active')[0], 'active');
+                    const oldActive = this.parentNode.getElementsByClassName('active');
+                    if (oldActive.length > 0) {
+                        // find old active and remove it
+                        fragmentString = jsOMS.trim(
+                            fragmentString.replace(oldActive[0].getElementsByTagName('label')[0].getAttribute('for'), ''),
+                            ','
+                        );
+
+                        jsOMS.removeClass(oldActive[0], 'active');
+                    }
+
+                    // remove new element if new element already inside, alternatively check for existence and don't do a new push state?
+                    // todo: here is a bug or in the uri factory. replace also replaces substrings e.g. #test-c-tab-1 gets partially replaced
+                    // by c-tab-1. either search for #c-tab-1 or ,c-tab-1 to be certain. That's not possible because it doesn't start with `#`
+                    fragmentString = jsOMS.trim(
+                        fragmentString.replace(this.getElementsByTagName('label')[0].getAttribute('for'), ''),
+                        ','
+                    );
+
                     jsOMS.addClass(this, 'active');
 
                     /* Add selected tab */
-                    window.history.pushState(null,'',
+                    window.history.pushState(null, '',
                         jsOMS.Uri.UriFactory.build(
                             '{%}#' + (fragmentString === '' ? '' : fragmentString + ',') + this.getElementsByTagName('label')[0].getAttribute('for')
                         )
                     );
                 });
             }
+
+            this.activateTabUri(e);
         };
 
         /**
diff --git a/Uri/UriFactory.js b/Uri/UriFactory.js
index 9d50aea..4830035 100644
--- a/Uri/UriFactory.js
+++ b/Uri/UriFactory.js
@@ -153,24 +153,11 @@
             const fragments = url.match(/\#[a-zA-Z0-9\-,]+/g),
                 fragLength = fragments !== null ? fragments.length : 0;
 
-            for (let i = 0; i < fragLength; ++i) {
+            for (let i = 0; i < fragLength - 1; ++i) {
+                // remove all from old url
                 url = url.replace(fragments[i], '');
             }
 
-            if (fragLength > 0) {
-                const fragList = fragments[fragLength - 1].split(','),
-                    fragListLength = fragList.length;
-                let fragListNew = [];
-
-                for (let i = 0; i < fragListLength; ++i) {
-                    if (!fragListNew.includes(fragList[i]) && fragList[i] !== '') {
-                        fragListNew.push(fragList[i]);
-                    }
-                }
-
-                url += fragListNew.join(',');
-            }
-
             return url;
         };
 
diff --git a/Utils/UiUtils.js b/Utils/UiUtils.js
index f3445c5..a50dc84 100644
--- a/Utils/UiUtils.js
+++ b/Utils/UiUtils.js
@@ -47,7 +47,7 @@
     jsOMS.addClass = function (ele, cls)
     {
         if (!jsOMS.hasClass(ele, cls)) {
-            ele.className += " " + cls;
+            ele.className += ele.className !== '' ? " " + cls : cls;
         }
     };
 
diff --git a/Utils/oLib.js b/Utils/oLib.js
index 4aca28a..9c747ae 100644
--- a/Utils/oLib.js
+++ b/Utils/oLib.js
@@ -171,7 +171,7 @@
     jsOMS.addClass = function (ele, cls)
     {
         if (!jsOMS.hasClass(ele, cls)) {
-            ele.className += " " + cls;
+            ele.className += ele.className !== '' ? " " + cls : cls;
         }
     };