WordPress 4.5 completely broke the website

You’ve provided no useful information to help us to help you figure out what your problem is. So let’s run through a few questions:

What’s your website’s url?

Which theme are you using?

Have you tried temporarily deactivating all plugins? Then reactivating them one by one to find the culprit.

Have you tried temporarily switching to a different theme, in case the theme is the problem?

Are there any error messages?

Have you tried switching on php debugging mode?

Yes, its basically broken the JS files of the custom theme.
No AJAX or effects are working.

When you say “yes” do you mean yes, you’ve tried all of thing things I suggested above.

Yes, disable everything still the buttons and all stop working.
It only works with wordpress default theme.

the JS files of the custom theme….

It’s simply not possible for anyone to help with code we can’t see and/or is not in a theme or plugin available from www.ads-software.com and that we have access to.

We have lost 3 days of business for this s**tty upgrade…

And that attitude discourages anyone from trying to help.

Have you used the developer tools in Firefox (or Firebug) or Chrome or Safari or IE to check for Javascript and other console errors?

everything works with default theme, but as soon as I activate my theme forest theme, everything is messed.

And the theme developer is saying, he has non issues.

Commercial and paid themes like ThemeForest themes are not supported here. You need to get an update from the theme developer. You paid for support when you bought the theme, so you have to contact the people who sold you the theme. These forums are for free themes available in the WordPress theme directory at https://www.ads-software.com/themes/. See https://codex.www.ads-software.com/Forum_Welcome#Commercial_Products

But why 4.5 happened with that conflict ?

Before 4.5, upgrade was never an issue.
That means, something changed in 4.5 majorly ?

https://www.ads-software.com/support/topic/read-this-first-wordpress-45-master-list

Read: https://www.ads-software.com/support/topic/read-this-first-wordpress-45-master-list

WordPress 4.5 has been in beta for nearly 2 months; it has been tested and tested again by volunteers and the problems most of you are describing can usually be associated with things covered in our Master List, such as the jQuery 1.12 problems.