jQuery is not defined after upgrading kentico 8.0 to 8.2

I suppose it's a file in the content tree. What Live url is shown for the Pages -> Images -> Logo -> Properties -> General page? Could you please also share your Settings -> Urls and SEO section?

I'm not even able to login so I cannot provide you with this information.

Javascript log is here:

Uncaught ReferenceError: jQuery is not defined
Uncaught ReferenceError: jQuery is not defined
Uncaught TypeError: $ is not a function
Uncaught ReferenceError: jQuery is not defined
Uncaught TypeError: $ is not a function
Uncaught ReferenceError: jQuery is not defined
Uncaught ReferenceError: jQuery is not defined
Uncaught TypeError: Cannot read property 'getElementsByTagName' of null
Uncaught TypeError: $ is not a function
Uncaught ReferenceError: jQuery is not defined
Uncaught TypeError: $ is not a function
Uncaught TypeError: Cannot read property 'fn' of undefined
Uncaught TypeError: $ is not a function
GET http://localhost:1469/Images/logo-v3.aspx?width=112&height=114 404 (Not Found)
GET http://localhost:1469/Images/user_expert.aspx?width=50&height=50&ext=.png 404 (Not Found)
Uncaught TypeError: $ is not a function
GET http://localhost:54435/__browserLink/requestData/ff3e1ea8e3a14bddb2fb2194f9ab01fe?version=2 
XMLHttpRequest cannot load http://localhost:54435/__browserLink/requestData/ff3e1ea8e3a14bddb2fb2194f9ab01fe?version=2. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:1469' is therefore not allowed access. The response had HTTP status code 404.

When I try to login via /CMSPages/logon.aspx I got these errors upon loading the logon page:

browserLink:37 GET http://localhost:54435/__browserLink/requestData/5d7f591fc21b45a69b6ff10b60f7d3a8?version=2 
    send    @   browserLink:37
    ajax    @   browserLink:37
    ht  @   browserLink:66
    dispatchCallback    @   browserLink:64
    (anonymous function)    @   browserLink:69
    (anonymous function)    @   browserLink:62
    dispatch    @   browserLink:37
    h   @   browserLink:37
    trigger @   browserLink:37
    triggerHandler  @   browserLink:37
    triggerReceived @   browserLink:62
    (anonymous function)    @   browserLink:62
    each    @   browserLink:37
    processMessages @   browserLink:62
    e.socket.e.socket.onmessage @   browserLink:62

XMLHttpRequest cannot load http://localhost:54435/__browserLink/requestData/5d7f591fc21b45a69b6ff10b60f7d3a8?version=2. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:1469' is therefore not allowed access. The response had HTTP status code 404.

The error says that your localhost:1469 site is requesting localhost:54435 and your browser ended the connection because of cross origin security issue. The requesting url is probably hardcoded somewhere. Do you have any customization there? Did the upgrade finish well (is there UPGRADE - Finish event logged in the Event log)? Anyway, I recommend to roll back and fix original issues before upgrading.